X-ray apparatus and controlling method of the same

ABSTRACT

An X-ray apparatus including an X-ray source configured to radiate X-rays; a collimator configured to adjust an irradiation region of X-rays radiated from the X-ray source; an image acquirer configured to acquire an image by imaging an object; and a controller configured to detect, in the image, a marker projected on the object by the collimator, and to determine a source to object distance (SOD) based on a location of the marker in the image, wherein the SOD comprises a distance between the X-ray source and the object.

CROSS-REFERENCE TO RELATED APPLICATION

This application claims priority from Korean Patent Applications No.10-2015-0089097, filed on Jun. 23, 2015, and No. 10-2016-0075106, filedon Jun. 16, 2016, in the Korean Intellectual Property Office, thedisclosures of which are incorporated herein by reference in theirentireties.

BACKGROUND

1. Field

The present disclosure relates to an X-ray apparatus and a controllingmethod of the same, and more particularly, to an X-ray apparatus thatmay determine a distance between an X-ray source and a target, and acontrolling method of the same.

2. Description of the Related Art

X-rays are electromagnetic waves which may generally have a wavelengthof 0.01 to 100 angstrom (Å). Because X-rays may be transmitted throughan object, X-rays are widely used in medical apparatuses capturingimages of the insides of bodies, non-invasive examination devices invarious general fields, and the like.

An X-ray apparatus may acquire an X-ray image by transmitting X-raysemitted from an X-ray source through a target, and detecting anintensity difference of the transmitted X-rays by using an X-raydetector. An inner structure of the target may be identified anddiagnosis of the object may be performed by using the X-ray image. TheX-ray apparatus may be advantageous for conveniently understanding theinner structure of the object by utilizing the fact that a transmissionrate of X-rays varies according to a density of the object and an atomicnumber of atoms that form the object. When X-rays have shortwavelengths, the transmission rate increases and images have improvedbrightness.

SUMMARY

Provided are an X-ray apparatus that may determine a distance between anX-ray source and a target, and a controlling method of the same.

Additional aspects will be set forth in part in the description whichfollows and, in part, will be apparent from the description, or may belearned by practice of the presented exemplary embodiments.

According to an aspect of an exemplary embodiment, an X-ray apparatusincludes an X-ray source configured to radiate X-rays; a collimatorconfigured to adjust an irradiation region of X-rays radiated from theX-ray source; an image acquirer configured to acquire an image byimaging an object; and a controller configured to detect, in the image,a marker projected on the object by the collimator, and to determine asource to object distance (SOD) based on a location of the marker in theimage, wherein the SOD includes a distance between the X-ray source andthe object.

The marker can represent at least one from among a center of crossinglines of the collimator projected on the object by the collimator when alamp of the collimator illuminates the object, or a point projected onthe object by a laser emitter of the collimator.

The image acquirer may be further configured to acquire anon-illuminated image by imaging the object while the object is notilluminated by the lamp of the collimator or the laser pointer, and thecontroller may be further configured to detect the marker using adifference image generated from the image and the non-illuminated image.

The controller may be further configured to detect the marker based oninformation about an epipolar line including a path along which themarker in the image is able to move.

The controller may be further configured to determine the SOD based oninformation about a location of the marker according to at least onefrom among locations of the object, a focal distance of a lens used forimaging the object, and an angle between the collimator and the lens.

The X-ray apparatus may further include a memory configured to storeinformation about a relationship between a location of the marker in theimage and the SOD, and the controller may be further configured todetermine the SOD based on the information stored in the memory.

The controller may be further configured to determine a thickness of theobject based on the SOD, and to determine an irradiation condition ofthe X-ray source based on the thickness of the object.

The X-ray apparatus may further include an output interface configuredto display the irradiation condition determined by the controller.

The X-ray apparatus may further include an input interface configured toreceive a user input setting the irradiation condition by approving orchanging the irradiation condition displayed by the output interface.

The controller may be further configured to control the X-ray source toradiate X-rays according to the irradiation condition set by the userinput.

The image acquirer may be further configured to acquire a detector imageby imaging an X-ray detector, and the controller may be furtherconfigured to detect a marker projected by the collimator from thedetector image, to determine a source to image receptor distance (SID)based on a location of the marker in the detector image, and todetermine a difference between the SOD and the SID as the thickness ofthe object, wherein the SID is a distance between the X-ray source andthe X-ray detector.

According to another aspect of an exemplary embodiment, a method ofcontrolling an X-ray apparatus including an X-ray source and acollimator includes acquiring an image by imaging an object; detecting,in the image, a marker projected on the object by the collimator of theX-ray apparatus; and determining a source to object distance (SOD) basedon a location of the marker in the image, wherein the SOD includes adistance between the object and the X-ray source of the X-ray apparatus.

The marker may represent at least one from among a center of crossinglines projected on the object by the collimator when a lamp of thecollimator illuminates the object, or a point projected on the object bya laser emitter of the collimator.

The method may further include acquiring a non-illuminated image byimaging the object while the object is not illuminated by the lamp ofthe collimator or the laser pointer, and the detecting of the markerincludes detecting the marker using a difference image generated fromthe image and the non-illuminated image.

The detecting of the marker includes detecting the marker based oninformation about an epipolar line including a path along which themarker in the image is able to move.

The determining of the SOD includes determining the SOD based oninformation about a location of the marker according to at least onefrom among locations of the object, a focal distance of a lens used forimaging the object, and an angle between the collimator and the lens.

The method may further include storing information about a relationshipbetween a location of the marker in the image and the SOD, and thedetermining of the SOD includes determining the SOD based on theinformation stored in the memory.

The method may further include: determining a thickness of the objectbased on the SOD; and determining an irradiation condition of the X-raysource based on the thickness of the object.

The method may further include displaying the determined irradiationcondition.

The method may further include receiving a user input setting theirradiation condition by approving or changing the irradiation conditiondisplayed on the output interface.

The method may further include controlling the X-ray source to radiateX-rays according to the irradiation condition set by the user input.

According to yet another aspect of an exemplary embodiment, anon-transitory computer-readable recording medium may have recordedthereon a program, which, when executed by a computer, causes thecomputer to perform the methods described herein.

According to a further aspect of an exemplary embodiment, a workstationconfigured to control an X-ray apparatus including an X-ray source and acollimator includes a communicator configured to receive an image byimaging an object from the X-ray apparatus; and a controller configuredto detect, in the image, a marker projected on the object by thecollimator, and to determine a source to object distance (SOD) based ona location of the marker in the image, wherein the SOD comprises adistance between the X-ray source and the object.

BRIEF DESCRIPTION OF THE DRAWINGS

These and other aspects will become apparent and more readilyappreciated from the following description of the exemplary embodiments,taken in conjunction with the accompanying drawings in which:

FIG. 1 is a block diagram of an X-ray system, according to an exemplaryembodiment;

FIG. 2 is a perspective view of a fixed type X-ray apparatus, accordingto an exemplary embodiment;

FIG. 3 is a diagram showing a configuration of a mobile X-ray apparatus,according to an exemplary embodiment;

FIG. 4 is a schematic diagram showing a detailed configuration of adetector, according to an exemplary embodiment;

FIG. 5 is a block diagram of an X-ray apparatus according to anexemplary embodiment;

FIG. 6A is a diagram of an example of the X-ray radiator, FIG. 6B is adiagram of an example of a shutter included in the collimator, and FIG.6C is a perspective view of an example of the collimator included in theX-ray apparatus of FIG. 5, according to an exemplary embodiment;

FIG. 7 is a diagram showing the X-ray apparatus of FIG. 5 according toan exemplary embodiment;

FIG. 8 is a diagram showing an object image acquired by the X-rayapparatus of FIG. 7, according to an exemplary embodiment;

FIG. 9 is a graph of a relationship information between a size of acollimation region and an object distance, according to an exemplaryembodiment;

FIG. 10 is a diagram for describing acquiring a detector distance byusing the X-ray apparatus of FIG. 7, according to an exemplaryembodiment;

FIG. 11 is a diagram showing a detector image acquired by the X-rayapparatus of FIG. 10, according to an exemplary embodiment;

FIG. 12 is a diagram showing a relationship between an object distance,a detector distance, and a thickness of an object in the graph of FIG. 9that shows relationship information, according to an exemplaryembodiment;

FIG. 13 is a block diagram of an X-ray apparatus, according to anexemplary embodiment;

FIG. 14 is a diagram of an X-ray apparatus, according to an exemplaryembodiment;

FIG. 15 is a diagram for describing acquiring of a detector distance bythe X-ray apparatus of FIG. 14, according to an exemplary embodiment;

FIGS. 16 to 18 are diagrams of irradiation conditions that are output ona manipulator of the X-ray apparatus of FIG. 13, according to anexemplary embodiment;

FIG. 19 is a table of first relationship information that may be storedin a memory of the X-ray apparatus of FIG. 13, according to an exemplaryembodiment;

FIG. 20 is a table of second relationship information that may be storedin a memory of the X-ray apparatus of FIG. 13, according to an exemplaryembodiment;

FIG. 21 is a diagram for describing acquiring of a collimation region inan object image by using the X-ray apparatus of FIG. 6, according to anexemplary embodiment;

FIG. 22 is a block diagram of an X-ray system, according to an exemplaryembodiment;

FIGS. 23 and 24 show manipulation of a workstation of FIG. 22, accordingto an exemplary embodiment;

FIGS. 25 to 29 are flowcharts of an operation method of an X-ray system,according to an exemplary embodiment;

FIG. 30 is a diagram of an X-ray apparatus, according to an exemplaryembodiment;

FIGS. 31A to 31C are examples of detector images acquired by an imageacquirer of FIG. 30, according to exemplary embodiments;

FIGS. 32A to 32C are examples of detector images and an object image,according to exemplary embodiments;

FIG. 33 is a diagram of an X-ray apparatus, according to an exemplaryembodiment;

FIG. 34 is a diagram for describing a location of a marker in an imageof a target when the target is moving in a space, according to anexemplary embodiment;

FIGS. 35A to 35C are examples of images of an object according todistances between an X-ray source and the object, according to exemplaryembodiments;

FIG. 36 is a diagram of an X-ray apparatus, according to an exemplaryembodiment;

FIGS. 37A to 37E are diagrams for describing an example of detecting amarker in an image of a target;

FIG. 38 is a diagram for describing a location of a marker in an imageof a target, according to an exemplary embodiment;

FIG. 39 is a diagram of an X-ray apparatus, according to an exemplaryembodiment;

FIG. 40 is a block diagram of an X-ray apparatus, according to anexemplary embodiment;

FIG. 41 is another exemplary block diagram of the X-ray apparatus ofFIG. 40;

FIGS. 42A and 42B are exemplary diagrams of an output interface in theX-ray apparatus of FIG. 41, according to exemplary embodiments; and

FIG. 43 is a block diagram of an X-ray apparatus, according to anotherexemplary embodiment

FIG. 44 is a flowchart of a method of controlling an X-ray system,according to an exemplary embodiment.

DETAILED DESCRIPTION

The attached drawings for illustrating exemplary embodiments of thepresent disclosure are referred to in order to gain a sufficientunderstanding of the present disclosure, the merits thereof, and theobjectives accomplished by the implementation of the present disclosure.The present disclosure may, however, be embodied in many different formsand should not be construed as being limited to the exemplaryembodiments set forth herein; rather, these exemplary embodiments areprovided such that this disclosure will be thorough and complete, andwill fully convey concepts to one of ordinary skill in the art. As usedherein, the term “and/or” includes any and all combinations of one ormore of the associated listed items. Expressions such as “at least oneof,” when preceding a list of elements, modify the entire list ofelements and do not modify the individual elements of the list.

Hereinafter, the terms used in the specification will be brieflydescribed, and then the present disclosure will be described in detail.

The terms used in this specification are those general terms currentlywidely used in the art in consideration of functions regarding thepresent disclosure, but the terms may vary according to the intention ofthose of ordinary skill in the art, precedents, or new technology in theart. Also, specified terms may be selected by the applicant, and in thiscase, the detailed meaning thereof will be described in the detaileddescription. Thus, the terms used in the specification should beunderstood not as simple names but based on the meaning of the terms andthe overall description.

Throughout the specification, an “image” may denote multi-dimensionaldata composed of discrete image elements (for example, pixels in atwo-dimensional image and voxels in a three-dimensional image). Forexample, an image may be a medical image of an object acquired by anX-ray apparatus, a computed tomography (CT) apparatus, a magneticresonance imaging (MRI) apparatus, an ultrasound diagnosis apparatus, oranother medical imaging apparatus.

In addition, an “object” may be a human, an animal, or a part of a humanor animal. For example, the object may include an organ (for example,the liver, the heart, the womb, the brain, breasts, or the abdomen),blood vessels, or a combination thereof. The object may be a phantom.The term “phantom” may denote a material having a volume, a density, andan effective atomic number that are approximately the same as those of aliving organism. For example, the phantom may be a spherical phantomhaving similar properties to those of the human body.

Throughout the specification, a “user” may be, but is not limited to, amedical expert, for example, a medical doctor, a nurse, a medicallaboratory technologist, or a medical imaging expert, or a technicianwho repairs medical apparatuses.

An X-ray apparatus may be a medical imaging apparatus that acquiresimages of internal structures of an object by transmitting an X-raythrough the human body. The X-ray apparatus may acquire medical imagesof an object more simply within a shorter time than other medicalimaging apparatuses including an MRI apparatus and a CT apparatus.Therefore, the X-ray apparatus is widely used in simple chest imaging,simple abdomen imaging, simple skeleton imaging, simple nasal sinusesimaging, simple neck soft tissue imaging, and breast imaging, amongother imaging situations.

FIG. 1 is a block diagram of an exemplary embodiment of an X-ray system1000. Referring to FIG. 1, the example X-ray system 1000 includes anX-ray apparatus 100 and a workstation 110. The X-ray apparatus 100 shownin FIG. 1 may be a fixed-type X-ray apparatus or a mobile X-rayapparatus. The X-ray apparatus 100 may include an X-ray radiator 120, ahigh voltage generator 121, a detector 130, a manipulator 140, and acontroller 150. The controller 150 may control overall operations of theX-ray apparatus 100.

The high voltage generator 121 may generate a high voltage forgenerating X-rays, and apply the high voltage to an X-ray source 122.

The X-ray radiator 120 includes the X-ray source 122 receiving the highvoltage from the high voltage generator 121 to generate and radiateX-rays, and a collimator 123 for guiding a path of the X-ray radiatedfrom the X-ray source 122 and adjusting an X-ray irradiation region.

The X-ray source 122 includes an X-ray tube that may be a vacuum tubediode including a cathode and an anode. An inside of the X-ray tube isset as a high vacuum state of about 10 mmHg, and a filament of the anodeis heated to a high temperature to generate thermal electrons. Thefilament may be a tungsten filament, and a voltage of about 10V and acurrent of about 3 to 5 A may be applied to an electric wire connectedto the filament to heat the filament.

In addition, when a high voltage of, for example, about 10 to about 300kVp is applied between the cathode and the anode, the thermal electronsare accelerated to collide with a target material of the cathode, andthen, an X-ray is generated. The X-ray is radiated outside via a window,and the window may be formed of a beryllium thin film. In this case,most of the energy of the electrons colliding with the target materialmay be consumed as heat, and remaining energy converted into the X-ray.

The cathode may be mainly formed of copper, and the target material maybe disposed opposite to the anode. The target material may be a highresistive material such as chromium (Cr), iron (Fe), cobalt (Co), nickel(Ni), tungsten (W), or molybdenum (Mo). The target material may berotated by a rotating field. When the target material is rotated, anelectron impact area is increased, and a heat accumulation rate per unitarea may be increased to be at least ten times greater than that of acase where the target material is fixed.

The voltage applied between the cathode and the anode of the X-ray tubemay be referred to as a tube voltage, and the tube voltage is appliedfrom the high voltage generator 121 and a magnitude of the tube voltagemay be expressed by a crest value (kVp). When the tube voltageincreases, a velocity of the thermal electrons increases, andaccordingly, an energy of the X-ray (energy of photon) that is generatedwhen the thermal electrons collide with the target material isincreased. The current flowing in the X-ray tube may be referred to as atube current that may be expressed as an average value (mA). When thetube current increases, the number of thermal electrons emitted from thefilament is increased, and accordingly, the X-ray dose (the number ofX-ray photons) generated when the thermal electrons collide with thetarget material is increased.

Therefore, the energy of the X-ray may be adjusted according to the tubevoltage, and the intensity of the X-ray or the X-ray dose may beadjusted according to the tube current and the X-ray exposure time.

The detector 130 detects an X-ray that is radiated from the X-rayradiator 120 and has been transmitted through an object. The detector130 may be a digital detector. The detector 130 may be implemented byusing a thin film transistor (TFT) or a charge coupled device (CCD).Although the detector 130 is included in the X-ray apparatus 100 in FIG.1, the detector 130 may be an X-ray detector that is a separate devicecapable of being connected to or separated from the X-ray apparatus 100.

The X-ray apparatus 100 may further include a manipulator 140 forproviding a user with an interface for manipulating the X-ray apparatus100. The manipulator 140 may include an output interface 141 and aninput interface 142. The input interface 142 may receive from a user acommand for manipulating the X-ray apparatus 100 and various types ofinformation related to X-ray imaging. The controller 150 may control ormanipulate the X-ray apparatus 100 according to the information receivedby the input interface 142. The output interface 141 may, for example,output sound representing information related to an imaging operationsuch as the X-ray radiation under the control of the controller 150.

The workstation 110 and the X-ray apparatus 100 may be connected to eachother by wire or wirelessly. When they are connected to each otherwirelessly, a device for synchronizing clock signals with each other maybe further included. The workstation 110 and the X-ray apparatus 100 mayexist within physically separate spaces.

The workstation 110 may include an output interface 111, an inputinterface 112, and a controller 113. The output interface 111 and theinput interface 112 provide a user with an interface for manipulatingthe workstation 110 and the X-ray apparatus 200. The controller 113 maycontrol the workstation 110 and the X-ray apparatus 200.

The X-ray apparatus 100 may be controlled via the workstation 110 or maybe controlled by the controller 150 included in the X-ray apparatus 100.Accordingly, a user may control the X-ray apparatus 100 via theworkstation 110 or may control the X-ray apparatus 100 via themanipulator 140 and the controller 150 included in the X-ray apparatus100. In other words, a user may remotely control the X-ray apparatus 100via the workstation 110 or may directly control the X-ray apparatus 100.

Although the controller 113 of the workstation 110 is separate from thecontroller 150 of the X-ray apparatus 100 in FIG. 1, FIG. 1 is only anexample. As another example, the controllers 113 and 150 may beintegrated into a single controller, and the single controller may beincluded in only one of the workstation 110 and the X-ray apparatus 100.Hereinafter, the controllers 113 and 150 may denote at least one fromamong the controller 113 of the workstation 110 and the controller 150of the X-ray apparatus 100.

The output interface 111 and the input interface 112 of the workstation110 may provide a user with an interface for manipulating the X-rayapparatus 100, and the output interface 141 and the input interface 142of the X-ray apparatus 100 may also provide a user with an interface formanipulating the X-ray apparatus 100. Although the workstation 110 andthe X-ray radiation apparatus 100 include the output interfaces 111 and141, respectively, and the input interfaces 112 and 142, respectively,in FIG. 1, exemplary embodiments are not limited thereto. Only one ofthe workstation 110 and the X-ray apparatus 100 may include an outputinterface or an input interface.

Hereinafter, the input interfaces 112 and 142 may denote at least onefrom among the input interface 112 of the workstation 110 and the inputinterface 142 of the X-ray apparatus 100, and the output interfaces 111and 141 may denote at least one from among the output interface 111 ofthe workstation 110 and the output interface 141 of the X-ray apparatus100.

Examples of the input interfaces 112 and 142 may include a keyboard, amouse, a touch screen, a voice recognizer, a fingerprint recognizer, aniris recognizer, and other input devices which are well known to one ofordinary skill in the art. The user may input a command for radiatingthe X-ray via the input interfaces 112 and 142, and the input interfaces112 and 142 may include a switch for inputting the command. In someexemplary embodiments, the switch may be configured so that a radiationcommand for radiating the X-ray may be input only when the switch ispushed twice.

In other words, when the user pushes the switch, a prepare command forperforming a pre-heating operation for X-ray radiation may be inputthrough the switch, and then, when the user pushes the switch once more,the radiation command for performing substantial X-ray radiation may beinput through the switch. When the user manipulates the switch asdescribed above, the controllers 113 and 150 generate signalscorresponding to the commands input through the switch manipulation,that is, for example, a prepare signal, and transmit the generatedsignals to the high voltage generator 121 generating a high voltage forgenerating the X-ray.

When the high voltage generator 121 receives the prepare signal from thecontrollers 113 and 150, the high voltage generator 121 starts apre-heating operation, and when the pre-heating is finished, the highvoltage generator 121 outputs a ready signal to the controllers 113 and150. In addition, the detector 130 also needs to prepare to detect theX-ray, and thus the high voltage generator 121 performs the pre-heatingoperation and the controllers 113 and 150 transmit a prepare signal tothe detector 130 so that the detector 130 may prepare to detect theX-ray transmitted through the object. The detector 130 prepares todetect the X-ray in response to the prepare signal, and when thepreparing for the detection is finished, the detector 130 outputs aready signal to the controllers 113 and 150.

When the pre-heating operation of the high voltage generator 121 isfinished and the detector 130 is ready to detect the X-ray, thecontrollers 113 and 150 transmit a radiation signal to the high voltagegenerator 121, the high voltage generator 121 generates and applies thehigh voltage to the X-ray source 122, and the X-ray source 122 radiatesthe X-ray.

When the controllers 113 and 150 transmit the radiation signal to thehigh voltage generator 121, the controllers 113 and 150 may transmit asound output signal to the output interfaces 111 and 141 so that theoutput interfaces 111 and 141 output a predetermined sound and theobject may recognize the radiation of the X-ray. The output interfaces111 and 141 may also output a sound representing information related toimaging in addition to the X-ray radiation. In FIG. 1, the outputinterface 141 is included in the manipulator 140; however, the exemplaryembodiments are not limited thereto, and the output interface 141 or aportion of the output interface 141 may be located elsewhere. Forexample, the output interface 141 may be located on a wall of anexamination room in which the X-ray imaging of the object is performed.

The controllers 113 and 150 control locations of the X-ray radiator 120and the detector 130, imaging timing, and imaging conditions, accordingto imaging conditions set by the user.

In more detail, the controllers 113 and 150 control the high voltagegenerator 121 and the detector 130 according to the command input viathe input interfaces 112 and 142 in order to control radiation timing ofthe X-ray, an intensity of the X-ray, and a region radiated by theX-ray. In addition, the control units 113 and 150 adjust the location ofthe detector 130 according to a predetermined imaging condition, andcontrols operation timing of the detector 130.

Furthermore, the controllers 113 and 150 generate a medical image of theobject by using image data received via the detector 130. In detail, thecontrollers 113 and 150 may receive the image data from the detector130, and then, generate the medical image of the object by removingnoise from the image data and adjusting a dynamic range and interleavingof the image data.

The output interfaces 111 and 141 may output the medical image generatedby the controllers 113 and 150. The output interfaces 111 and 141 mayoutput information that is necessary for the user to manipulate theX-ray apparatus 100, for example, a user interface (UI), userinformation, or object information. Examples of the output interfaces111 and 141 may include a speaker, a printer, a cathode ray tube (CRT)display, a liquid crystal display (LCD), a plasma display panel (PDP),an organic light emitting diode (OLED) display, a field emission display(FED), a light emitting diode (LED) display, a vacuum fluorescentdisplay (VFD), a digital light processing (DLP) display, a flat paneldisplay (FPD), a three-dimensional (3D) display, a transparent display,and other various output devices well known to one of ordinary skill inthe art.

The workstation 110 shown in FIG. 1 may further include a communicatorthat may be connected to a server 162, a medical apparatus 164, and aportable terminal 166 via a network 15.

The communicator may be connected to the network 15 by wire orwirelessly to communicate with the server 162, the medical apparatus164, or the portable terminal 166. The communicator may transmit orreceive data related to diagnosis of the object via the network 15, andmay also transmit or receive medical images captured by the medicalapparatus 164, for example, a CT apparatus, an MRI apparatus, or anX-ray apparatus. Moreover, the communicator may receive a medicalhistory or treatment schedule of an object (e.g., a patient) from theserver 162 to diagnose a disease of the object. Also, the communicatormay perform data communication with the portable terminal 166 such as amobile phone, a personal digital assistant (PDA), or a laptop computerof a medical doctor or a client, as well as the server 162 or themedical apparatus 164 in a hospital.

The communicator may include one or more elements enabling communicationwith external apparatuses. For example, the communicator may include alocal area communication module, a wired communication module, and awireless communication module.

The local area communication module may refer to a module for performinglocal area communication with an apparatus located within apredetermined distance. Examples of local area communication technologymay include, but are not limited to, a wireless local area network(LAN), Wi-Fi, Bluetooth, ZigBee, Wi-Fi Direct (WFD), ultra wideband(UWD), infrared data association (IrDA), Bluetooth low energy (BLE), andnear field communication (NFC).

The wired communication module may refer to a module for communicatingby using an electric signal or an optical signal. Examples of wiredcommunication technology may include wired communication techniquesusing a pair cable, a coaxial cable, and an optical fiber cable, andother wired communication techniques that are well known to one ofordinary skill in the art.

The wireless communication module transmits and receives a wirelesssignal to and from at least one selected from a base station, anexternal apparatus, and a server in a mobile communication network.Here, examples of the wireless signal may include a voice call signal, avideo call signal, and various types of data according totext/multimedia messages transmission.

The X-ray apparatus 100 shown in FIG. 1 may include a plurality ofdigital signal processors (DSPs), an ultra-small calculator, and aprocessing circuit for special purposes (for example, high speedanalog/digital (A/D) conversion, high speed Fourier transformation, andan array process).

In addition, communication between the workstation 110 and the X-rayapparatus 100 may be performed using a high speed digital interface,such as low voltage differential signaling (LVDS), asynchronous serialcommunication, such as a universal asynchronous receiver transmitter(UART), a low latency network protocol, such as error synchronous serialcommunication or a controller area network (CAN), or any of othervarious communication methods that are well known to one of ordinaryskill in the art.

FIG. 2 is a perspective view of an example of a fixed type X-rayapparatus 200 according to an exemplary embodiment. The fixed type X-rayapparatus 200 may be another exemplary embodiment of the X-ray apparatus100 of FIG. 1. Components included in the fixed type X-ray apparatus 200that are the same as those of the X-ray apparatus 100 of FIG. 1 use thesame reference numerals, and repeated descriptions thereof will beomitted.

Referring to FIG. 2, the example fixed type X-ray apparatus 200 includesa manipulator 140 providing a user with an interface for manipulatingthe X-ray apparatus 200, an X-ray radiator 120 radiating an X-ray to anobject, a detector 130 detecting an X-ray that has passed through theobject, first, second, and third motors 211, 212, and 213 providing adriving power to transport the X-ray radiator 120, a guide rail 220, amoving carriage 230, and a post frame 240. The guide rail 220, themoving carriage 230, and the post frame 240 are formed to transport theX-ray radiator 120 by using the driving power of the first, second, andthird motors 211, 212, and 213.

The guide rail 220 includes a first guide rail 221 and a second guiderail 222 that are provided to form a predetermined angle with respect toeach other. The first guide rail 221 and the second guide rail 222 mayrespectively extend in directions crossing each other at 90°.

The first guide rail 221 is provided on the ceiling of an examinationroom in which the X-ray apparatus 200 is disposed.

The second guide rail 222 is located under the first guide rail 221, andis mounted so as to slide along the first guide rail 221. A roller thatmay move along the first guide rail 221 may be provided on the firstguide rail 221. The second guide rail 222 is connected to the roller tomove along the first guide rail 221.

A first direction D1 is defined as a direction in which the first guiderail 221 extends, and a second direction D2 is defined as a direction inwhich the second guide rail 222 extends. Therefore, the first directionD1 and the second direction D2 cross each other at 90°, and may beparallel to the ceiling of the examination room.

The moving carriage 230 is disposed under the second guide rail 222 soas to move along the second guide rail 222. A roller moving along thesecond guide rail 222 may be provided on the moving carriage 230.

Therefore, the moving carriage 230 may move in the first direction D1together with the second guide rail 222, and may move in the seconddirection D2 along the second guide rail 222.

The post frame 240 is fixed on the moving carriage 230 and located underthe moving carriage 230. The post frame 240 may include a plurality ofposts 241, 242, 243, 244, and 245.

In some exemplary embodiments, the plurality of posts 241, 242, 243,244, and 245 are connected to each other to be foldable, nestable, orretractable within each other, and thus, the post frame 240 may have alength that is adjustable in a vertical direction of the examinationroom while in a state of being fixed to the moving carriage 230.

A third direction D3 is defined as a direction in which the length ofthe post frame 240 increases or decreases. Therefore, the thirddirection D3 may be perpendicular to the first direction D1 and thesecond direction D2.

The detector 130 detects the X-ray that has passed through the object,and may be combined with a receptor 290 disposed in a table or areceptor 280 disposed in a stand.

A rotating joint 250 is disposed between the X-ray radiator 120 and thepost frame 240. The rotating joint 250 allows the X-ray radiator 120 tobe coupled to the post frame 240, and supports a load applied to theX-ray radiator 120.

The X-ray radiator 120 connected to the rotating joint 250 may rotate ona plane that is perpendicular to the third direction D3. In this case, arotating direction of the X-ray radiator 120 may be defined as a fourthdirection D4.

Also, the X-ray radiator 120 may be configured to be rotatable on aplane perpendicular to the ceiling of the examination room. Therefore,the X-ray radiator 120 may rotate in a fifth direction D5 that is arotating direction about an axis that is parallel with the firstdirection D1 or the second direction D2, with respect to the rotatingjoint 250.

The first, second, and third motors 211, 212, and 213 may be provided tomove the X-ray radiator 120 in the first, second, and third directionsD1, D2, and D3. The first, second, and third motors 211, 212, and 213may be electrically driven, and the first, second, and third motors 211,212, and 213 may respectively include an encoder.

The first, second, and third motors 211, 212, and 213 may be disposed atvarious locations in consideration of design convenience. For example,the first motor 211, moving the second guide rail 222 in the firstdirection D1, may be disposed around the first guide rail 221, thesecond motor 212, moving the moving carriage 230 in the second directionD2, may be disposed around the second guide rail 222, and the thirdmotor 213, increasing or reducing the length of the post frame 240 inthe third direction D3, may be disposed in the moving carriage 230. Inanother example, the first, second, and third motors 211, 212, and 213may be connected to a power transfer unit in order to linearly move theX-ray radiator 120 in the first, second, and third directions D1, D2,and D3. The driving power transfer unit may be a combination of a beltand a pulley, a combination of a chain and a sprocket, or a shaft, whichare generally used.

In another example, motors may be disposed between the rotating joint250 and the post frame 240 and between the rotating joint 250 and theX-ray radiator 120 in order to rotate the X-ray radiator 120 in thefourth and fifth directions D4 and D5.

The manipulator 140 may be disposed on a side surface of the X-rayradiator 120.

Although FIG. 2 shows the fixed type X-ray apparatus 200 connected tothe ceiling of the examination room, the fixed type X-ray apparatus 200is merely an example for convenience of comprehension. That is, X-rayapparatuses according to exemplary embodiments of the present disclosuremay include X-ray apparatuses having various structures that are wellknown to one of ordinary skill in the art, for example, a C-arm-typeX-ray apparatus and an angiography X-ray apparatus, in addition to thefixed type X-ray apparatus 200 of FIG. 2.

FIG. 3 is a diagram showing an example configuration of a mobile X-rayapparatus 300 capable of performing an X-ray imaging operationregardless of a place where the imaging operation is performed,according to an exemplary embodiment. The mobile X-ray apparatus 300 maybe another exemplary embodiment of the X-ray apparatus 100 of FIG. 1.Components included in the mobile X-ray apparatus 300 that are the sameas those of the X-ray apparatus 100 of FIG. 1 use the same referencenumerals as those used in FIG. 1, and a repeated description thereofwill be omitted.

Referring to FIG. 3, the example mobile X-ray apparatus 300 includes atransport unit 370 including a wheel for transporting the mobile X-rayapparatus 300, a main unit 305, an X-ray radiator 120, and a detector130 detecting an X-ray that is radiated from the X-ray radiator 120toward an object and transmitted through the object. The main unit 305includes a manipulator 140 providing a user with an interface formanipulating the mobile X-ray apparatus 300, a high voltage generator121 generating a high voltage applied to an X-ray source 122, and acontroller 150 controlling overall operations of the mobile X-rayapparatus 300. The X-ray radiator 120 includes the X-ray source 122generating the X-ray, and a collimator 123 guiding a path along whichthe generated X-ray is emitted from the X-ray source 122 and adjustingan irradiation region radiated by the X-ray.

The detector 130 in FIG. 3 may be not combined with any receptor, andthe detector 130 may be a portable detector which can exist anywhere.

In FIG. 3, the manipulator 140 is included in the main unit 305;however, exemplary embodiments are not limited thereto. For example, asillustrated in FIG. 2, the manipulator 140 of the mobile X-ray apparatus300 may be disposed on a side surface of the X-ray radiator 120.

The controller 150 controls locations of the X-ray radiator 120 and thedetector 130, imaging timing, and imaging conditions according toimaging conditions set by the user.

In addition, the controller 150 generates a medical image of the objectby using image data received from the detector 130. In detail, thecontroller 150 may generate the medical image of the object by removingnoise from the image data received from the detector 130 and adjusting adynamic range and interleaving of the image data.

The main unit 305 of the mobile X-ray apparatus 300 shown in FIG. 3 mayfurther include an output interface outputting the medical imagegenerated by the controller 150. The output interface may outputinformation that is necessary for the user to manipulate the mobileX-ray apparatus 300, for example, a UI, user information, or objectinformation.

FIG. 4 is a schematic diagram showing an example of a detailedconfiguration of a detector 400, according to an exemplary embodiment.The detector 400 may be an exemplary embodiment of the detector 130 ofFIGS. 1-3. The detector 400 may be an indirect type detector.

Referring to FIG. 4, the detector 400 may include a scintillator, aphotodetecting substrate 410, a bias driver 430, a gate driver 450, anda signal processor 470.

The scintillator receives the X-ray radiated from the X-ray source 122and converts the X-ray into light.

The photodetecting substrate 410 receives the light from thescintillator and converts the light into an electrical signal. Thephotodetecting substrate 410 may include gate lines GL, data lines DL,TFTs 412, photodiodes 414, and bias lines BL.

The gate lines GL may be formed in a first direction DR1, and the datalines DL may be formed in a second direction DR2 that crosses the firstdirection DR1. The first direction DR1 and the second direction DR2 mayintersect perpendicularly to each other. FIG. 4 shows four gate lines GLand four data lines DL as an example.

The TFTs 412 may be arranged as a matrix in the first and seconddirections DR1 and DR2. Each of the TFTs 412 may be electricallyconnected to one of the gate lines GL and one of the data lines DL. Agate of the TFT 412 may be electrically connected to the gate line GL,and a source of the TFT 412 may be electrically connected to the dataline DL. In FIG. 4, sixteen TFTs 412 (in a 4×4 arrangement) are shown asan example.

The photodiodes 414 may be arranged as a matrix in the first and seconddirections DR1 and DR2 so as to respectively correspond to the TFTs 412.Each of the photodiodes 414 may be electrically connected to one of theTFTs 412. An N-side electrode of each of the photodiodes 414 may beelectrically connected to a drain of the TFT 412. FIG. 4 shows sixteenphotodiodes 414 (in a 4×4 arrangement) as an example.

The bias lines BL are electrically connected to the photodiodes 414.Each of the bias lines BL may be electrically connected to P-sideelectrodes of an array of photodiodes 414. For example, the bias linesBL may be formed to be substantially parallel with the second directionDR2 so as to be electrically connected to the photodiodes 414. On theother hand, the bias lines BL may be formed to be substantially parallelwith the first direction DR1 in order to be electrically connected tothe photodiodes 414. FIG. 4 shows four bias lines BL formed along thesecond direction DR2 as an example.

The bias driver 430 is electrically connected to the bias lines BL inorder to apply a driving voltage to the bias lines BL. The bias driver430 may selectively apply a reverse bias voltage or a forward biasvoltage to the photodiodes 414. A reference voltage may be applied tothe N-side electrodes of the photodiodes 414. The reference voltage maybe applied via the signal processor 470. The bias driver 430 may apply avoltage that is less than the reference voltage to the P-side electrodesof the photodiodes 414 in order to apply a reverse bias voltage to thephotodiodes 414. On the other hand, the bias driver 430 may apply avoltage that is greater than the reference voltage to the P-sideelectrodes of the photodiodes 414 so as to apply a forward bias voltageto the photodiodes 414.

The gate driver 450 is electrically connected to the gate lines GL andthus may apply gate signals to the gate lines GL. For example, when thegate signals are applied to the gate lines GL, the TFTs 412 may beturned on by the gate signals. On the other hand, when the gate signalsare not applied to the gate lines GL, the TFTs 412 may be turned off.

The signal processor 470 is electrically connected to the data lines DL.When the light received by the photodetecting substrate 410 is convertedinto the electrical signal, the electrical signal may be read out by thesignal processor 470 via the data lines DL.

An operation of the detector 400 will now be described. During theoperation of the detector 400, the bias driver 430 may apply the reversebias voltage to the photodiodes 414.

While the TFTs 412 are turned off, each of the photodiodes 414 mayreceive the light from the scintillator and generate electron-hole pairsto accumulate electric charges. The amount of electric chargeaccumulated in each of the photodiodes 414 may correspond to theintensity of the received X-ray.

Then, the gate driver 450 may sequentially apply the gate signals to thegate lines GL along the second direction DR2. When a gate signal isapplied to a gate line GL and thus TFTs 412 connected to the gate lineGL are turned on, photocurrents may flow into the signal processor 470via the data lines DL due to the electric charges accumulated in thephotodiodes 414 connected to the turned-on TFTs 412.

The signal processor 470 may convert the received photocurrents intoimage data and output the image data to the outside. The image data maybe in the form of an analog signal or a digital signal corresponding tothe photocurrents.

Although not shown in FIG. 4, if the detector 400 shown in FIG. 4 is awireless detector, the detector 400 may further include a battery unitand a wireless communication interface unit.

FIG. 5 is a block diagram of an example of an X-ray apparatus 500according to an exemplary embodiment. The X-ray apparatus 500 of FIG. 5may be another exemplary embodiment of the above-described X-rayapparatuses 100, 200, and 300. Therefore, whether or not describedbelow, the above-described features may be applied to the X-rayapparatus 500 of FIG. 5. Also, the X-ray apparatus 500 may be controlledby the workstation 110 of FIG. 1.

Referring to FIG. 5, the X-ray apparatus 500 may include an imageacquirer 510, an X-ray radiator 520, a detector 530, and a controller550. The X-ray radiator 520 includes an X-ray source 522 and acollimator 523. Furthermore, a controller included in a workstation mayperform the function of the controller 550.

The X-ray source 522 may radiate X-rays to an object. The collimator 523may adjust an irradiation region of X-rays radiated by the X-ray source522. The detector 530 detects X-rays. Hereinafter in the presentspecification, a detector may also be referred to as an “X-raydetector.” Although FIG. 5 illustrates that the detector 530 is includedin the X-ray apparatus 500, the detector 530 may be an X-ray detectorthat may be connected to or separated from the X-ray apparatus 500.

The collimator 523 includes a lamp 524. The lamp 524 may be turned onand off. The lamp 524 may include various types of light emissionsources. When the lamp 524 is turned on, light is emitted from the lamp524.

The image acquirer 510 may acquire an image of an object by imaging anobject while the lamp 524 is turned on. Hereinafter, the image acquiredby imaging the object is referred to as “object image.” The object imageis captured via imaging, and is different from an X-ray image that isacquired by capturing an object using X-rays. The image acquirer 510 mayinclude various types of imaging devices, such as a camera or acamcorder.

The controller 550 may include a central processing unit (CPU), amicroprocessor, a graphic processing unit (GPU), and the like.Furthermore, the controller 550 may include a memory storing programs orinformation for performing the operations mentioned above and following.

The controller 550 may acquire a distance between the X-ray source 522and the object based on the object image acquired by the image acquirer510. Hereinafter, a distance between an X-ray source and an object isreferred to as “object distance” or “source to object distance (SOD).”

The controller 550 may detect a certain area or a certain point in anobject image. According to a relationship between a region and the SODor a relationship between a point and the SOD, the controller 550 mayacquire the SOD based on a detected region or a detected point. A methodof acquiring an object distance based on an object image will bedescribed below with reference to the following drawings.

The controller 550 may acquire a thickness of the object based on theobject distance, and a detector distance that is a distance between theX-ray source 522 and the detector 530. Hereinafter, a distance betweenan X-ray source and a detector is also referred to as “detectordistance” or “source to image receptor distance SID.”

FIG. 6A is a diagram of an example of the X-ray radiator 520, FIG. 6B isa diagram of an example of a shutter 526 included in the collimator 523,and FIG. 6C is a perspective view of an example of the collimator 523included in the X-ray apparatus 500 of FIG. 5, according to an exemplaryembodiment.

Referring to FIGS. 5 and 6A, the collimator 523 may include anirradiation window 525, a shutter 526 and a lamp 524. The irradiationwindow 525 may be disposed on an outside surface of the collimator 523,and the shutter 526 and the lamp 524 may be disposed inside thecollimator 523. The collimator 523 may further include a mirror 527 toreflect light from the lamp 524. As shown in FIG. 6B, the shutter 526may include a plurality of movable blades to adjust an X-ray irradiationregion.

X-rays may be radiated from the X-ray source 522 through the irradiationwindow 525 of the collimator 523. Also, when the lamp 524 disposed onthe side of the collimator 523 is turned on, light is emitted throughthe mirror 527 and the irradiation window 525 of the collimator 523.That is, light from the lamp 524 or X-rays from the X-ray source 522 maypass through the irradiation window 525. Referring to FIG. 6, theirradiation window 525 is a quadrilateral with crossing lines. However,FIG. 6 is only an exemplary diagram of the irradiation window 525, and ashape of the irradiation window 525 is not limited to that shown in FIG.6.

The shutter 526 may adjust a size of the irradiation region of X-rays orlight from the lamp 524 irradiated through the irradiation window 525.The collimator 523 may adjust an X-ray irradiation region by controllingthe shutter 526.

Because light from the lamp 524 and X-rays from the X-ray source 522 areemitted through the irradiation window 525, an irradiation region oflight from the lamp 524 may correspond to the X-ray irradiation region.Therefore, before the X-ray source 522 radiates X-rays, a user mayrecognize or adjust the X-ray irradiation region via the irradiationregion of light from the lamp 524.

As shown in FIGS. 6A and 6C, the image acquirer 510 may be coupled tothe collimator 523. In more detail, the image acquirer 510 may beapproximately located on a center of an edge of the plane of thecollimator from which X-rays are irradiated. However, FIG. 6C is only anexemplary diagram, and a location of the image acquirer 510 in the X-rayapparatus 500 is not limited to that shown in FIG. 6.

FIG. 7 is a diagram showing an example of the X-ray apparatus 500 ofFIG. 5 according to an exemplary embodiment. Whether or not describedbelow, the X-ray apparatus 500 of FIG. 7 may also include theabove-described features. Also, features of FIGS. 5 and 6 that are notshown in FIG. 7 may also be included in the X-ray apparatus 500 of FIG.7. The X-ray apparatus 500 of FIG. 7 may include the controller 550 ofFIG. 5, and the X-ray radiator 520 of FIG. 7 may include the collimator523 including the lamp 524 and the X-ray source 522 of FIG. 5.

Referring to FIGS. 5 and 7, when the lamp 524 is turned on, light fromthe lamp 524 is emitted through the irradiation window 525 of thecollimator 523. The irradiation window 525 may have a particular shape,such as crossing lines. Due to an irradiation region 590 of light fromthe lamp 524, an image IM100 of the irradiation window 525 having theparticular shape may be formed on an object 10. The image of theirradiation window 525 formed on the object 10 may also be referred toas an “irradiation window image IM100” on the object 10.

The image acquirer 510 may acquire an object image by imaging the object10. Because the irradiation window image IM100 is formed on the object10, the object image acquired by the image acquirer 510 may include anarea of the irradiation window image IM100.

FIG. 8 is a diagram showing an example of an object image 30 acquired bythe X-ray apparatus 500 of FIG. 7, according to an exemplary embodiment.

Referring to FIGS. 7 and 8, the object image 30 includes an image area31 corresponding to the irradiation window image IM100 formed on theobject 10. Hereinafter, the area 31 of the irradiation window imageIM100 in the object image 30 will be referred to as “collimation region”or “irradiation region of a collimator” of the object image 30. That is,a collimation region 31 is included in the object image 30 andcorresponds to the irradiation region 590 of light from the lamp 524 ofthe collimator 523 of FIG. 5.

The object image 30 may indicate 2-dimensional (2D) data including pixelvalues of pixels that are discrete image components. The pixel valuesmay include at least one piece of information, such as brightness orcolor. In the object image 30, the collimation region 31 may be a groupof pixels.

Referring back to FIGS. 5 to 8, the controller 550 may detect thecollimation region 31 in the object image 30. The controller 550 mayacquire an object distance SOD based on a size of the collimation region31.

The controller 550 may detect the collimation region 31 based onbrightness information of the object image 30. The collimation region 31may be brighter than other areas in the object image 30. That is, pixelvalues of pixels in the collimation region 31 may have higher brightnessthan those of other areas.

Furthermore, the controller 550 may detect the collimation region 31based on a shape of the irradiation window 525 of the collimator 523.The shape of the collimation region 31 may vary according to the shapeof the irradiation window 525. For example, when the irradiation window525 is quadrilateral-shaped as in FIG. 6, the collimation region 31 mayalso be quadrilateral-shaped. Also, when the irradiation window 525 hascrossing lines as in FIG. 6, the collimation region 31 may also havecrossing lines L1 and L2 as shown in FIG. 8. Therefore, the controller550 may use a pattern recognition algorithm based on the shape of theirradiation window 525 to detect the collimation region 31. For example,when the irradiation window 525 is quadrilateral-shaped, the controller550 may use a quadrilateral pattern recognition algorithm.

The controller 550 may set a predetermined error range related to theshape of the collimation region 31 that is based on the shape of theirradiation window 525 of the collimator 523. Due to curves of theobject 10, the irradiation window image IM100 on the object 10 may beslightly distorted compared to an actual shape of the irradiation window525. Accordingly, the shape of the collimation region 31 in the objectimage 30 may also be distorted. Therefore, the controller 550 may set apredetermined error range related to the shape of the collimation region31. For example, when the irradiation window 525 is rectangular-shaped,the shape of the collimation region 31 may be a quadrilateral such as atrapezoid.

Also, the controller 550 may reduce the size of the irradiation window525 by using the shutter 526 so as to reduce distortion of the shape ofthe collimation region 31. In this case, the collimation region 31 mayalso be reduced in the object image 30, and thus, the shape of thecollimation region 31 may be less distorted. However, as the collimationregion 31 decreases in size, accuracy of the object distance SODacquired by the controller 550 may decrease. Therefore, the controller550 may adjust the size of the irradiation window 525 of FIG. 6 based ontrade-off with the accuracy of the object distance SOD.

Accordingly, the controller 550 may detect the collimation region 31based on brightness information of the object image 30, the shape of theirradiation window 525, and the like. The controller 550 may acquire theobject distance SOD based on the size of the collimation region 31. Thesize of the collimation region 31 may correspond to the number of pixelsin the collimation region 31.

Alternatively, the size of the collimation region 31 may correspond tothe area size of the collimation region 31. The controller 550 maydetect crossing lines L1 and L2 of the object image 30 that correspondto crossing lines of the irradiation window 525, and acquire the size ofthe collimation region 31 based on the crossing lines L1 and L2. Thecontroller 550 may detect the crossing lines L1 and L2 based on thebrightness information of the object image 30, the shape of theirradiation window 525, and the like. The controller 550 may detectrespective lengths of the crossing lines L1 and L2. For example, therespective lengths of the crossing lines L1 and L2 may correspond to thenumber of pixels that form each of the crossing lines L1 and L2. Thecontroller 550 may multiply the respective lengths of the crossing linesL1 and L2 and thus acquire the size of the collimation region 31.

Alternatively, the size of the collimation region 31 may be estimatedbased on a length of one of the crossing lines L1 and L2. The controller550 may acquire the size of the collimation region 31 based on a lengthof one of the crossing lines L1 and L2 of the irradiation window 525.

The controller 550 may acquire the object distance SOD based on the sizeof the collimation region 31. However, the descriptions above are onlyexamples of a method of acquiring the size of the collimation region 31,and the method is not limited thereto.

The size of the collimation region 31 in the object image 30 may varyaccording to the object distance SOD. Therefore, when the controller 550acquires relationship information that indicates relationship betweenthe size of the collimation region 31 and the object distance SOD, theobject distance SOD may be acquired based on the relationshipinformation.

FIG. 9 is a graph of an example of a relationship information between asize of a collimation region and an object distance, according to anexemplary embodiment.

Referring to FIG. 9, an X-axis indicates the object distance, and aY-axis indicates a size of a collimation region in an object imageobtained by the image acquirer. The size of the collimation decreases asthe object distance increases. In perspective, the size of thecollimation region in the object image may decrease as the objectdistance increases. Therefore, when the size (OA) of the collimationregion in the object image is acquired, the object distance SOD may beacquired based on the relationship information as shown in FIG. 9.

Referring back to FIG. 7, the controller 550 of FIG. 5 may acquire theobject distance SOD based on relationship information (e.g., therelationship information of FIG. 9) that indicates a relationshipbetween the size of the collimation region and the object distance.Also, the controller 550 of FIG. 5 may acquire an object thickness OTthat indicates a thickness of the object 10, based on a detectordistance SID (source to image receptor distance) and an object distanceSOD. The object thickness OT may be equal to a difference between thedetector distance SID and the object distance SOD.

Therefore, according to an exemplary embodiment, the X-ray apparatus 500may automatically acquire the object distance SOD, which is a distancebetween an X-ray source 525 and the object 10, based on an object imageby imaging the object 10. Also, the X-ray apparatus 500 may acquire theobject thickness OT based on the object distance SOD and the detectordistance SID, which is a distance between the X-ray source 525 and thedetector 530. According to an exemplary embodiment, the X-ray apparatus500 may automatically acquire the object distance SOD or the objectthickness OT without a separate sensor or a measuring instrument such asa tapeline.

Also, the controller 550 of FIG. 5 may acquire the detector distance SIDin a similar manner as the acquiring of the object distance SOD. Thiswill be described with reference to FIG. 10.

FIG. 10 is a diagram for describing an example of acquiring the detectordistance SID by using the X-ray apparatus 500 of FIG. 7, according to anexemplary embodiment. The X-ray apparatus 500 of FIG. 10 may be anotherexemplary embodiment of the X-ray apparatus 500 of FIG. 5. Theabove-described features may also be applied to the X-ray apparatus 500.

Referring to FIGS. 5 and 10, as shown there is no object between theX-ray radiator 520 and the detector 530. When the lamp 524 is turned on,light from the lamp is emitted through the irradiation window 525 of thecollimator 523. Due to the irradiation region 590 of light from the lamp524, an image IM200 of the irradiation window 525 having a particularshape, such as crossing lines, may be formed on the detector 530. Theimage of the irradiation window 525 formed on the detector 530 may bereferred to as “irradiation window image IM200.”

The image acquirer 510 may acquire a detector image by imaging thedetector 530. In this case, the irradiation window image IM200 may beformed on the detector 530. Therefore, the detector image acquired bythe image acquirer 510 may include an image area corresponding to theirradiation window image IM200.

FIG. 11 is a diagram showing an example of a detector image 20 acquiredby the X-ray apparatus 500 of FIG. 10, according to an exemplaryembodiment.

Referring to FIGS. 10 and 11, the detector image 20 includes an imagearea 21 corresponding to the irradiation window image IM200 formed onthe detector 530. Hereinafter, the image area 21 corresponding to theirradiation window image IM200 in the detector image 20 is referred toas “collimation region” of the detector image 20. That is, thecollimation region 21 is included in the detector image 20 andcorresponds to the irradiation region 590 of light emitted from the lamp524 of the collimator 523 of FIG. 5.

The controller 550 of the X-ray apparatus 500 of FIG. 5 may detect thecollimation region 21 from the detector image 20. The controller 550 ofFIG. 5 may detect the collimation region 21 based on brightnessinformation of the detector image 20, the shape of the irradiationwindow 525, and the like. The controller 550 of FIG. 5 may acquire thedetector distance SID based on a size of the collimation region 21. Thesize of the collimation region 21 may correspond to the number of pixelsin the collimation region 21.

Alternatively, the size of the collimation region 21 may correspond tothe area size of the collimation region 21. The controller 550 of FIG. 5may detect crossing lines L3 and L4 of the detector image 20 thatcorrespond to the crossing lines of the irradiation window 525, andacquire the size of the collimation region 21 based on the crossinglines L3 and L4. The controller 550 of FIG. 5 may detect respectivelengths of the crossing lines L3 and L4. For example, the respectivelengths of the crossing lines L3 and L4 may correspond to the number ofpixels that form each of the crossing lines L3 and L4. The controller550 of FIG. 5 may multiply the respective lengths of the crossing linesL3 and L4 and thus acquire the size of the collimation region 21.

Alternatively, the size of the collimation region 21 may be estimatedbased on a length of one of the crossing lines L3 and L4. The controller550 of FIG. 5 may acquire the size of the collimation region 21 based ona length of one of the crossing lines L3 and L4.

The controller 550 of FIG. 5 may acquire the detector distance SID basedon the size of the collimation region 21. However, the descriptionsabove are only examples of a method of acquiring the size of thecollimation region 21, and the method is not limited thereto.

As in the acquiring of the object distance SOD, the controller 550 ofFIG. 5 may acquire the detector distance SID based on relationshipinformation that indicates a relationship between a size of acollimation region and a detector distance.

The controller 550 of FIG. 5 may use the relationship information (e.g.,the relationship information of FIG. 9) that indicates the relationshipbetween the size of the collimation region and the object distance,which is used for the acquiring of the object distance SOD, to acquirethe detector distance SID. The relationship information may beinformation that is acquired based on values that are measured inadvance through experiments.

In FIG. 5, the image acquirer 510 of the X-ray apparatus 500 may acquiretarget images by imaging a target at various distances while changing adistance between the X-ray source 522 and a target. The target may bethe object or the detector 530. The X-ray apparatus 500 may detect asize of a collimation region of each of the target images acquiredaccording to distances. By doing so, the X-ray apparatus 500 may acquirethe relationship information (e.g., the relationship information of FIG.9) between the size of the collimation region and the distance betweenthe X-ray source 522 and the target in advance. Alternatively, the X-rayapparatus 500 may receive relationship information that is acquired byanother external device through experiments.

FIG. 12 is a diagram showing an example of a relationship between anobject distance SOD, a detector distance SID, and a thickness OT of anobject in the graph of FIG. 9 that shows relationship information,according to an exemplary embodiment.

Referring to FIG. 12, when a size OA of the collimation region isacquired from the object image, the object distance SOD may be acquiredbased on the relationship information. Likewise, when a size DA of thecollimation region of the detector image is acquired from the detectorimage, the detector distance SID may be acquired. The object thicknessOT may be acquired based on a difference between the detector distanceSID and the object distance SOD.

As described above, the controller 550 of FIG. 5 may acquire thedetector distance SID by using a method similar to the method ofacquiring the object distance SOD. However, this is only an exemplaryembodiment of the method of acquiring the detector distance SID. Thecontroller 550 of FIG. 5 may acquire the detector distance SID invarious ways. For example, a detector may be coupled to a receptor suchas a table type receptor or a stand type receptor. An X-ray apparatusmay adjust or automatically acquire a distance between an X-ray sourceand the receptor by receiving location information of the X-ray sourceand the receptor from a sensor included in the X-ray apparatus to thecontroller. In this case, the X-ray apparatus may acquire the detectordistance SID by using a method different from the method of acquiringthe object distance SOD.

FIG. 13 is a block diagram of an example of an X-ray apparatus 600,according to an exemplary embodiment. The X-ray apparatus 600 of FIG. 13may be another exemplary embodiment of the X-ray apparatus 500 of FIG.5. Therefore, whether or not described below, the above-describedfeatures may be included in the X-ray apparatus 600 of FIG. 13.

Referring to FIG. 13, the X-ray apparatus 600 includes an image acquirer610, an X-ray radiator 620, and a controller 650. The X-ray radiator 620may include an X-ray source 622 and a collimator 623. The collimator 623includes a lamp 624. The X-ray apparatus 600 may further include adetector 630, a manipulator 640, and a memory 660. The manipulator 640may include an output interface 641 and an input interface 642.

The image acquirer 610 may acquire an object image by imaging an objectwhile the lamp 624 is turned on.

The controller 650 may acquire an object distance, which is a distancebetween the X-ray source 622 and the object, based on the object imageacquired by the image acquirer 610. The controller 650 may detect acollimation region from the object image, and acquire the objectdistance based on a size of the collimation region. The controller 650may acquire the object distance based on information stored in thememory 660, that is, information about a relationship between the sizeof the collimation region and a target distance which is a distancebetween an X-ray source 622 and a target. The target may be the objector the detector 630. The controller 650 may acquire an object thicknessbased on the object distance and a detector distance, which is adistance between the X-ray source 622 and the detector 630.

Also, based on the object thickness, the controller 650 may acquire anirradiation condition that is information related to an X-ray radiationamount of the X-ray source 622. The irradiation condition may refer toinformation that may affect the X-ray radiation amount. For example, theirradiation condition may include a tube voltage, tube current, and anX-ray radiation time of the X-ray source 622.

The irradiation condition may be thickness information based on athickness of the object. The thickness information may include thethickness of the object, or a degree of thickness of the object based onthe thickness of the object. An example of the degree of the thicknessmay include obesity. An appropriate amount of X-rays may increase as thethickness of the object increases. Therefore, the irradiation conditionmay include the thickness information.

Alternatively, the irradiation condition may be radiation amountinformation related to an X-ray radiation amount. The radiation amountinformation may include an X-ray radiation amount, power or voltagenecessary for irradiating X-rays according to the X-ray radiationamount, and the like.

As described above, the irradiation condition may include at least oneof the thickness information and the irradiation amount information.

The memory 660 may store information necessary for operations andcontrolling of the X-ray apparatus 600. The memory 660 may store firstrelationship information (e.g., the relationship information of FIG. 9)that indicates a relationship between the size of the collimation regionand the target distance. Also, the memory 660 may further store secondrelationship information that indicates a relationship between thethickness of the object and the X-ray radiation amount.

The output interface 641 may output the irradiation condition related tothe X-ray radiation amount.

The user may input X-ray setting information for setting the X-rayradiation amount via the input interface 642. The user may see theirradiation condition that is output on the output interface 641, andthen input the X-ray setting information. The X-ray setting informationmay include an X-ray radiation amount, power or voltage necessary toirradiate X-rays according to the X-ray radiation amount, and the like.That is, the X-ray setting information may include the same informationas the irradiation condition. However, the irradiation condition isoutput via the output interface 641, whereas the X-ray settinginformation is input by the user via the input interface 642.

When the user sets the X-ray radiation amount, the X-ray source 622 mayemit X-rays according to the set X-ray radiation amount.

FIG. 14 is a diagram of an example of an X-ray apparatus 700, accordingto an exemplary embodiment. The X-ray apparatus 700 of FIG. 14 may beanother exemplary embodiment of the X-ray apparatus 600 of FIG. 13.Therefore, whether or not described below, the above-described featuresmay also be applied to the X-ray apparatus 700 of FIG. 14. Componentsincluded in the X-ray apparatus 700 of FIG. 14 that are the same asthose of the X-ray apparatus 600 of FIG. 13 use the same referencenumerals as those used in FIG. 13, and a repeated description thereofwill be omitted. Also, the components of FIG. 13 that are notillustrated in FIG. 14 may be included in the X-ray apparatus 700 ofFIG. 14.

Referring to FIGS. 13 and 14, the example X-ray apparatus 700 includes aguide rail 720, a moving carriage 730, and a post frame 740 for movingthe X-ray radiator 620. Although not illustrated in FIG. 14, the X-rayradiator 620 includes the X-ray source 622 and the collimator 623including the lamp 624, as in FIG. 13.

Although the detector 630 of FIG. 14 is illustrated as being coupled toa table type receptor 690, the detector 630 may also be coupled to astand type receptor. Alternatively, the detector 630 may be a portabledetector that is not coupled to any receptor and located at any desiredlocation.

When the lamp 624 of the collimator 623 in the X-ray radiator 620 isturned on, light from the lamp 524 is radiated in a light irradiationregion 750. The image acquirer 610 may acquire an object image byimaging the object 10. The controller 650 may acquire an object distanceSOD based on the object image. The controller 650 may acquire an objectthickness OT based on a detector distance SID and the object distanceSOD.

The controller 650 may acquire the detector distance SID by usingvarious methods.

For example, the controller 650 may acquire the detector distance SIDbased on a moving distance of the post frame 740. The guide rail 720 maybe installed at a ceiling of an examination room. A height of the guiderail 720 and a height of the table type receptor 690 may be fixed. Alength of the post frame 740 may increase or decrease in the thirddirection D3. Therefore, the controller 650 may acquire the detectordistance SID when a moving distance of the post frame 740 is acquired.This example may not only be applied to a case of the detector 630coupled to the table type receptor 690 shown in FIG. 14, but also beapplied to a detector coupled to a stand type receptor.

As another example, the controller 650 may acquire the detector distanceSID according to a selection of the user. The user may input distancesetting information for setting the detector distance SID via the inputinterface 642. The controller 650 may move the post frame 740 accordingto the input of the user to move the X-ray radiator 620 to a locationcorresponding to the detector distance SID that is set. The distancesetting information that is input to the input interface 642 may be thedetector distance SID that the user desires, but is not limited thereto.For example, the distance setting information that is input to the inputinterface 642 may include an initialization instruction or an imagingpreparation instruction. The detector distance SID that corresponds tothe initialization instruction or the imaging preparation instructionmay be a preset value. According to the initialization instruction orthe imaging preparation instruction, the X-ray radiator 620 may be movedto a location that corresponds to the detector distance SID that ispreset. This example may also be applied to the case of the detector 630coupled to the table type receptor 690 as well as the detector coupledto the stand type receptor.

In some exemplary embodiments, as described above, the controller 650may acquire the detector distance SID by using a method similar to themethod of acquiring the object distance SOD. This will be described withreference to FIG. 15.

FIG. 15 is a diagram for describing an example of acquiring of adetector distance SID by the X-ray apparatus 700 of FIG. 14, accordingto an exemplary embodiment.

Referring to FIGS. 13 and 15, as shown there is no object between theX-ray radiator 620 and the detector 630. The image acquirer 610 mayacquire a detector image by imaging the detector 630 while the lamp 624is turned on. The image acquirer 610 of FIG. 15 may acquire the detectorimage by imaging a receptor 690 that is coupled to the detector 630.

The controller 650 may acquire a detector distance SID based on thedetector image acquired by the image acquirer 610. The detector distanceSID is a distance between the X-ray source 622 and the detector 630. Amethod of acquiring the detector distance SID based on the detectorimage may be applied to not only the detector 630 coupled to the tabletype receptor 690 as shown in FIG. 15, but also a detector that iscoupled to a stand type receptor. Alternatively, the method may beapplied to a portable detector that may be located at any desiredlocation.

After acquiring the detector distance SID based on the detector image,the controller 650 may adjust the acquired detector distance SID again.For example, a desired distance between the X-ray source 622 and thedetector 530 selected by the user may be 100 cm, and the detectordistance SID acquired by the controller 650 may be 80 cm. In this case,the controller 650 may move the post frame 740 upward by 20 cm in thethird direction D3.

As described above, the controller 650 may acquire an irradiationcondition based on an object thickness OT that is acquired based on anobject distance SOD and the detector distance SID. The irradiationcondition may be information related to an X-ray radiation amount of theX-ray source 622. The output interface 641 may output the irradiationcondition.

FIGS. 16 to 18 are diagrams of examples of irradiation conditions thatmay be output on the manipulator 640 of FIG. 13, according to anexemplary embodiment. The manipulator 640 includes the output interface641 and the input interface 642. Although FIGS. 16 to 18 illustrate thatthe output interface 641 and the input interface 642 in the manipulator640 are spaced apart, the output interface 641 and the input interface642 are not limited thereto. The input interface 642 or a portion of theinput interface 642 may be provided in the output interface 641. Forexample, when the input interface 642 includes a touch screen, the touchscreen may be provided in the output interface 641.

Referring to FIG. 16, an irradiation condition 50 that is output on theoutput interface 641 may be a thickness of an object. The irradiationcondition 50 may be output in text and numbers, for example, “THICKNESSOF OBJECT: 19.6 CM” as shown in FIG. 16.

Referring to FIG. 17, an irradiation condition 50 a that is output onthe output interface 641 may be obesity of the object. For example, thecontroller 650 of FIG. 13 may acquire the obesity of the object based onan object thickness. The obesity may be classified into a plurality oflevels, such as “high, intermediate, and low.” For example, theirradiation condition 50 a may be output in text, “OBESITY OF OBJECT:HIGH” as shown in FIG. 17.

FIGS. 16 and 17 are only examples of when the irradiation conditions 50and 50 a on the output interface 641 correspond to thicknessinformation. The output interface 641 may output the irradiationcondition in various ways such that the user may recognize the thicknessof the object, the degree of the thickness.

The user may input X-ray setting information for setting an X-rayradiation amount via the input interface 642 of FIGS. 16 and 17. Theuser may see the irradiation conditions 50 and 50 a via the outputinterface 641, and then input the X-ray setting information. Forexample, when the user determines that the thickness of the object ishigh based on the thickness information output via the irradiationconditions 50 and 50 a, the user may input the X-ray setting informationsuch that the X-ray radiation amount increases.

Referring to FIG. 18, an irradiation condition 70 output on the outputinterface 641 may include at least one of thickness information 71 andradiation amount information 72. The radiation amount information 72 maybe related to the X-ray radiation amount. The radiation amountinformation 72 may include the X-ray radiation amount, power or voltagenecessary for irradiating X-rays according to the X-ray radiationamount, and the like. For example, the irradiation condition may includea tube voltage, tube current, and an X-ray radiation time of an X-raysource.

The user may input the X-ray setting information for setting the X-rayradiation amount via the input interface 642. The user may see theirradiation condition 70 via the output interface 641, and then inputthe X-ray setting information.

As shown in FIG. 18, the input interface 642 may include a touch screen,and a user 90 may input the X-ray setting information by touching theradiation amount information 72 in the irradiation condition 70 that isdisplayed on the output interface 641. For example, the user 90 mayinput the X-ray setting information by approving the output radiationamount information 72 or readjusting the radiation amount information72. However, FIG. 18 is only an example of inputting the X-ray settinginformation. The method of inputting the X-ray setting information maybe modified in various ways.

Referring to FIG. 13, the memory 660 of the X-ray apparatus 600 maystore first relationship information (e.g., the relationship informationof FIG. 9) that indicates a relationship between a size of a collimationregion and a target distance. Also, the memory 660 may further storesecond relationship information that indicates a relationship betweenthe thickness of the object and the X-ray radiation amount.

FIG. 19 is an example table of first relationship information 40 thatmay be stored in the memory 660 of the X-ray apparatus 600 of FIG. 13,according to an exemplary embodiment.

Referring to FIG. 19, the first relationship information 40 may be tabletype information in which an SID 41, which indicates distanceinformation between an X-ray source and a target, is matched with aregion size 42, which indicates size information of a collimationregion. In FIG. 19, the target may be a detector. The first relationshipinformation 40 may store relationships between detector distances SIDand respective sizes of collimation regions in a detector image. Thatis, when the detector distance SID is a ‘first distance,’ the detectorimage is acquired and ‘first size’ is acquired as a size of acollimation region in the detector image. Accordingly, the firstrelationship information 40 may be acquired through experiments.

Here, it is assumed that the controller 650 of the X-ray apparatus 600of FIG. 13 detects a size of a collimation region in an object image ora detector image as ‘second size.’ The controller 650 may acquire thatan object distance or a detector distance is a ‘second distance’ basedon the first relationship information 40 stored in the memory 660.

FIG. 19 is only an example of the first relationship information 40. Asanother example, the first relationship information 40 stored in thememory 660 of FIG. 13 may be a relation formula of the x-axis and they-axis in the graph as in FIG. 9.

FIG. 20 is an example of a table of second relationship information 60that may be stored in the memory 660 of the X-ray apparatus 600 of FIG.13, according to an exemplary embodiment.

Referring to FIG. 20, the second relationship information 60 may be arelationship between thickness information 61 acquired based on athickness of an object and an irradiation condition 62 of an X-raysource. The thickness information 61 and the irradiation condition 62 ofFIG. 20 are only examples. The thickness information 61 may include thethickness of the object, a thickness range of the object, and a degreeof thickness of the object. The irradiation condition 62 may include anX-ray radiation amount, power or voltage necessary for irradiatingX-rays according to the X-ray radiation amount, and the like. Forexample, the irradiation condition may include a tube voltage, tubecurrent, and an X-ray radiation time of an X-ray source.

Here, it is assumed that the controller 650 of the X-ray apparatus 600of FIG. 13 detects the thickness of the object as ‘third thickness.’ Thecontroller 650 may acquire that radiation amount information 62 is‘third radiation amount’ based on the second relationship information 60stored in the memory 660.

The output interface 641 may output the irradiation condition thatincludes at least one of the thickness information 61 and the radiationamount information 62. The user may input X-ray setting information viathe input interface 642.

The X-ray source 622 may radiate X-rays according to an X-ray radiationamount that is set by the user.

However, the first relationship information 40 of FIG. 19 stored in thememory 660 may only apply when a size of the irradiation region of thecollimator 623 is limited to a specific size. The size of theirradiation region may be adjusted by using the shutter 526. However,due to a limit of the memory 660, the first relationship information 40may include respective sizes of collimation regions according to targetdistances, which are acquired through experiments only when the size ofthe irradiation region is specified.

Therefore, in some exemplary embodiments the collimator 623 may adjustthe size of the irradiation region to a first size while the object isbeing imaged. The first size may be a certain size at which the firstrelationship information is applied. Next, the collimator 623 may adjustthe size of the irradiation region to a second size while the X-raysource 622 radiates X-rays. The second size may be selected by the user.Therefore, the irradiation region may have different sizes while theobject is imaged and while the object is captured by using X-rays.

As described above, according to an exemplary embodiment, the X-rayapparatus 600 may acquire the thickness of the object based on theobject image. Also, the X-ray apparatus 600 may acquire informationrelated to the X-ray radiation amount, i.e., the irradiation condition,based on the thickness of the object, and output the irradiationcondition. Accordingly, the user may set the X-ray radiation amount ofthe X-ray source 622 that is appropriate for the object thickness byusing the output irradiation condition. That is, according to anexemplary embodiment, the X-ray apparatus 600 may automatically detectthe thickness of the object so as to guide the user to set the X-rayradiation amount that is appropriate for the thickness of the object.Thus, the user may use the X-ray apparatus more conveniently.

The X-ray apparatus 600 may detect a collimation region from the objectimage to acquire the thickness of the object.

FIG. 21 is a diagram for describing an example of acquiring of acollimation region in an object image by using the X-ray apparatus 600of FIG. 6, according to an exemplary embodiment.

Referring to FIGS. 13 and 21, the image acquirer 610 may acquire a firstobject image 81 by imaging an object while the lamp 624 is turned off.Also, the image acquirer 610 may acquire a second object image 82 byimaging the same object while the lamp 624 is turned on. FIG. 21 is anexample in which the object is a phantom, but exemplary embodiments arenot limited thereto.

The controller 650 may acquire a difference image 83 by performingsubtraction on the first object image 81 and the second object image 82.The controller 650 may detect a collimation region 84 from thedifference image 83. In the difference image 83, an area other than thecollimation region 84, i.e., a peripheral area may have very lowbrightness. The peripheral area may be substantially removed bysubtraction because respective peripheral areas of the first and secondobject images 81 and 82 have almost no difference in brightness. In thedifference image 83, because respective areas of the first and secondobject images 81 and 82 corresponding to the collimation region 84 havedifferent brightness, brightness of the collimation region 84 may beincreased by performing subtraction.

When a surrounding environment of the X-ray apparatus 600 is bright, thebrightness of the collimation region 84 in the second object image 82may be indifferent from that of the peripheral area. In this case, thecontroller 650 may detect the collimation region 84 from the differenceimage 83 based on not only the second object image 82 but also the firstobject image 81.

The controller 650 may monochromatize the first and second object images81 and 82. For example, through image processing, the controller 650 mayremove color information from the first and second object images 81 and82 so that only bright information remains. Next, the controller 650 mayacquire the difference image 83 from a monochromatized first objectimage and a monochromatized second object. Also, in order to detect thecollimation region 84, the controller 650 may perform an additionalimage processing on the difference image 83, for example, thresholdingor filtering. Also, when the irradiation window 525 of FIG. 6 isquadrilateral-shaped, the controller 650 may detect the collimationregion 84 by using a quadrilateral pattern recognition algorithm.

FIG. 21 shows only an exemplary embodiment of a method of detecting acollimation region from an object image, and the method of detecting thecollimation region is not limited thereto.

Heretofore, an X-ray apparatus according to an exemplary embodimentacquires an object thickness from an object image and outputs anirradiation condition. However, the exemplary embodiment may also beperformed in a workstation. That is, the above-described features mayalso be applied to a workstation.

FIG. 22 is a block diagram of an example of an X-ray system 8000,according to an exemplary embodiment.

Referring to FIG. 22, the X-ray system 8000 includes an X-ray apparatus800 and a workstation 860.

The example X-ray apparatus 800 includes an image acquirer 810 and anX-ray radiator 820. Also, the X-ray apparatus 800 may further include adetector 830. The X-ray radiator 820 includes an X-ray source 822 and acollimator 823. The collimator 823 includes a lamp 824. The X-rayapparatus 800 may include the features of the above-described X-rayapparatuses. Although not illustrated in FIG. 22, the X-ray apparatus800 may also include a manipulator or a controller as in theabove-described X-ray apparatuses.

The workstation 860 may include a controller 813 and a manipulator 840that provides a user interface (UI). The manipulator 840 may include anoutput interface 841 and an input interface 842.

The controller 813 and the manipulator 840 of the workstation 860 mayinclude the above-described features of the controllers and themanipulators of the X-ray apparatuses. A UI applied to the manipulator840 of the workstation 860 may be the same as a UI applied to amanipulator of an X-ray apparatus. Therefore, a simple and intuitive UImay be provided, and the user may intuitively and conveniently operateand control the X-ray apparatus 800.

The image acquirer 810 of the X-ray apparatus 800 may acquire an objectimage by imaging an object while the lamp 824 is turned on.

The controller 813 of the workstation 860 may receive the object imagefrom the X-ray apparatus 800. The workstation 860 may further include acommunicator that receives the object image from the X-ray apparatus800.

The controller 813 of the workstation 860 may turn on or off the lamp824 of the collimator 823. Also, the controller 813 may control a sizeof an irradiation region of the collimator 823 by controlling blades ofthe shutter of the collimator 823.

Based on the object image, the controller 813 may acquire an objectdistance that is a distance between the X-ray source 822 and the object.The controller 813 may acquire a thickness of the object based on theobject distance and a detector distance that is a distance between theX-ray source 822 and the detector 830. Based on the thickness of theobject, the controller 813 may acquire an irradiation condition that isinformation related to an X-ray radiation amount of the X-ray source822.

The output interface 641 of the workstation 860 may output theirradiation condition. The user may input X-ray setting information forsetting the X-ray radiation amount via the input interface 842.

The controller 813 of the workstation 860 may control the X-ray source822 of the X-ray apparatus 800 such that the X-ray source 822 radiatesX-rays according to the X-ray radiation amount. The controller 813 mayadjust the size of the irradiation window of the collimator 823 to afirst size while the object is being imaged, and adjust the size of theirradiation window to a second size while the X-ray source 822 radiatesX-rays.

Although not illustrated in FIG. 22, the workstation 860 or thecontroller 813 of the workstation 860 may further include a memory. Thememory of the workstation 860 may store relationship information (e.g.,the relationship information of FIG. 19) that indicates a relationshipbetween the size of the collimation region and the target distance.Also, the memory may further store second relationship information (forexample, the relationship information of FIG. 20) that indicates arelationship between the thickness of the object and the X-ray radiationamount.

FIGS. 23 and 24 show examples of the manipulator 840 of the workstation860 of FIG. 22, according to an exemplary embodiment.

Referring to FIG. 23, the manipulator 840 may output thicknessinformation as an irradiation condition 51. Referring to FIG. 24, themanipulator 840 may output at least one of thickness information 76 andradiation amount information 77 as an irradiation condition 75. The user90 may input X-ray setting information to the manipulator 840.

FIGS. 23 and 24 are only examples of the irradiation conditions that areoutput via the workstation 860. The irradiation conditions are notlimited thereto.

FIG. 25 is a flowchart of an example of an operation method S100 of anX-ray system, according to an exemplary embodiment.

Referring to FIG. 25, the X-ray system may acquire an object distancebased on an object image that is acquired by imaging an object while alamp of a collimator is turned on (S110). The object distance is adistance between an X-ray source and the object.

The X-ray system may acquire an object thickness based on the objectdistance and a detector distance that is a distance between the X-raysource and a detector (S120).

FIG. 26 is a flowchart of an example of an operation method S200 of anX-ray system, according to an exemplary embodiment.

Referring to FIG. 26, the X-ray system may acquire an object distancebased on an object image (S210). The X-ray system may acquire an objectthickness based on the object distance and a detector distance (S220).

Based on the object thickness, the X-ray system may acquire anirradiation condition that is information related to an X-ray radiationamount of an X-ray source (S230). The X-ray system may output theirradiation condition (S240).

FIG. 27 is a flowchart of an example of an operation method S300 of anX-ray system, according to an exemplary embodiment.

Referring to FIG. 27, the X-ray system may acquire an object distancebased on an object image (S310). The X-ray system may acquire an objectthickness based on the object distance and a detector distance (S320).The X-ray system may acquire an irradiation condition based on theobject thickness (S330). The X-ray system may output the irradiationcondition (S340).

The X-ray system may receive X-ray setting information for setting anX-ray radiation amount from a user (S350). The X-ray system may controlthe X-ray source such that the X-ray source radiates X-rays according tothe X-ray radiation amount (S360).

FIG. 28 is a flowchart of an example of an operation method S400 of anX-ray system, according to an exemplary embodiment.

Referring to FIG. 28, the X-ray system acquires a detector distancebased on a detector image that is acquired by imaging a detector while alamp is turned on (S410). The detector distance is a distance between anX-ray source and the detector. While imaging the detector, an objectdoes not exist between the detector and an X-ray radiator. Also, theX-ray system may readjust the distance between the X-ray source and thedetector based on the acquired detector distance.

The X-ray system may acquire an object distance based on an object image(S420). The object image may be acquired by imaging an object betweenthe detector and the X-ray radiator while the lamp is turned on. TheX-ray system may acquire an object thickness based on the objectdistance and the detector distance (S430).

FIG. 29 is a flowchart of an example of an operation method S500 of anX-ray system, according to an exemplary embodiment.

Referring to FIG. 29, the X-ray system may adjust a size of anirradiation region of a collimator to a first size (S510). The X-raysystem may acquire an object image by imaging an object while a lamp ofthe collimator is turned on (S520). The X-ray system may acquire anobject distance based on the object image (S530). The X-ray system mayacquire an object thickness based on the object distance and a detectordistance (S540). The X-ray system may acquire an irradiation conditionbased on the object thickness (S550). The X-ray system may output theirradiation condition (S560). The X-ray system may receive X-ray settinginformation from a user (S570). The X-ray system may adjust the size ofthe irradiation region of the collimator to a second size (S580). TheX-ray system may control an X-ray source such that the X-ray sourceradiates X-rays according to a set X-ray radiation amount (S590).

The operation methods of the X-ray systems described with reference toFIGS. 25 to 29 may be performed by an X-ray apparatus or a workstationconfigured to control the X-ray apparatus. Also, the above-describedfeatures may also be applied to the each step of the operation methods.

Next, referring to FIGS. 30 to 32, according to an exemplary embodiment,a method of acquiring an object distance or a detector distance based onan object image acquired by imaging an object or a detector imageacquired by imaging a detector. The exemplary embodiments describedbelow may be applied to the above-described examples in which the objectdistance or the detector distance is acquired based on the object imageor the detector image.

FIG. 30 is a diagram of an example of an X-ray apparatus 900, accordingto an exemplary embodiment.

Referring to FIG. 30, the X-ray apparatus 900 may include an imageacquirer 910, an X-ray radiator 920, and a detector 930. Although notillustrated in FIG. 30, the X-ray apparatus 900 may include thecomponents included in the X-ray apparatuses described above.

930-1, 930-2, and 930-3 are reference numerals indicating the detector930 at different positions. Also, SID-1, SID-2, and SID-3 referencenumerals indicating detector distances according to the positions of thedetector 930. The detector distance may refer to a distance between thedetector 930 and the X-ray radiator 920. For convenience, the followingterms will be used: first detector 930-1, second detector 930-2, thirddetector 930-3, first detector distance SID-1, second detector distanceSID-2, and third detector distance SID-3.

The image acquirer 910 may be located at a boundary of a side of theX-ray radiator 920. In more detail, the image acquirer 910 may beapproximately located on a center of an edge of the front plane of theX-ray radiator 920. In this case, as shown in FIG. 30, a line of sight(LOS) of the image acquirer 910 may be inclined, and a virtual cameraarea 990 of the image acquirer 910 may also be inclined.

FIGS. 31A to 31C are examples of detector images acquired by the imageacquirer 910 of FIG. 30.

FIG. 31A is a first detector image 85-1 acquired by capturing the firstdetector 930-1 of FIG. 30 at the first detector distance SID-1 from theimage acquirer 910, FIG. 31B is a second detector image 85-2 acquired bycapturing the second detector 930-2 at the second detector distanceSID-2 from the image acquirer 910, and FIG. 31C is a third detectorimage 85-3 acquired by capturing the third detector 930-3 at the thirddetector distance SID-3 from the image acquirer 910.

Referring to FIG. 30, the first detector distance SID-1 is the shortest,and the third detector distance SID-3 is the longest. Referring to FIG.31, a collimation region 80-1 of the first detector image 85-1 is thelargest, and a collimation region 80-3 of the third detector image 85-3is the smallest. That is, as the detector distances SID-1, SID-2, andSID-3 increase, sizes of the collimation regions 80-1, 80-2, and 80-3decrease, respectively. Therefore, the detector distances SID-1, SID-2,and SID-3 may be acquired based on the collimation regions 80-1, 80-2,and 80-3. Details regarding this are described above.

However, when the LOS of the image acquirer 910 is inclined as shown inFIG. 30, respective locations of centers P1, P2, and P3 of thecollimation regions 80-1, 80-2, and 80-3 in the detector images 85-1,85-2, and 85-3 may change. That is, as the detector distances SID-1,SID-2, and SID-3 increase, the respective locations of the centers P1,P2, and P3 of the collimation regions 80-1, 80-2, and 80-3 in thedetector images 85-1, 85-2, and 85-3 may be biased toward the left.

Therefore, the X-ray apparatus 900 may detect the respective locationsof the centers P1, P2, and P3 of the collimation regions 80-1, 80-2, and80-3 in the detector images 85-1, 85-2, and 85-3, and may acquire thedetector distances SID-1, SID-2, and SID-3 based on the respectivelocations of the detected centers P1, P2, and P3. Also, the X-rayapparatus 900 may store, in a memory (e.g., the memory 660 of FIG. 13),a database of location-distance information that indicates arelationship between the respective locations of the centers P1, P2, andP3 of the collimation regions 80-1, 80-2, and 80-3 and the detectordistances SID-1, SID-2, and SID-3. The X-ray apparatus 900 may performexperiments in advance to generate the database. For example, the X-rayapparatus 900 may acquire detector images by changing a detectordistance, acquire a location of a center of a collimation region of eachof the detector images, and store a relationship between the detectordistance and the respective locations of the centers aslocation-distance information.

When a collimator of the X-ray radiator 920 of FIG. 30 includes anirradiation window 525 with crossing lines as in FIG. 6, the collimationregions 80-1, 80-2, and 80-3 of the detector images 85-1, 85-2, and 85-3may also have crossing lines. The centers P1, P2, and P3 of thecollimation regions 80-1, 80-2, and 80-3 may be the same as the centerof the crossing lines. In this case, the X-ray apparatus 900 may detectthe centers P1, P2, and P3 of the collimation regions 80-1, 80-2, and80-3 by detecting respective centers of the crossing lines in thedetector image 85-1, 85-2, and 85-3. However, exemplary embodiments arenot limited thereto.

FIGS. 32A to 32C are examples of detector images and an object image.

FIGS. 32A and 32B respectively show a detector image 97 and an objectimage 98 having an identical detector distance. An X-ray apparatus mayacquire a thickness of an object based on a difference between alocation of a center P4 of a collimation region 91 of the detector image97 and a location of a center P5 of a collimation region 92 of theobject image 98.

Alternatively, the X-ray apparatus may acquire a detector distance basedon a location of a center P4 of the collimation region 91 of thedetector image 97, and acquire an object distance based on a location ofa center P5 of the collimation region 92 of the object image 98. Then,the X-ray apparatus may acquire a difference between the detectordistance and the object distance as the thickness of the object.

FIG. 32C is a detector image 99 acquired by imaging a detector at adetector distance that is the same as the object distance of FIG. 32B.For example, the detector distance of FIGS. 32A and 32B may both be 100cm, the object distance of FIG. 32B may be 80 cm, and the detectordistance of FIG. 32C may be 80 cm.

A location of a center P6 of a collimation region 93 of the detectorimage 99 may be the same as the location of the center P5 of thecollimation region 92 of the object image 98. That is, whether thetarget is an object or a detector, a distance from an X-ray source tothe target may be acquired based on a location of a center of acollimation region in a target image.

The above-described X-ray apparatus or a workstation that controls theX-ray apparatus may acquire a target distance by detecting a center of acollimation region from a target image.

Exemplary embodiments of a method of acquiring a distance between anX-ray source and a target based on a collimation region detected from animage of a target have been described above. According to anotherexemplary embodiment, a certain point, i.e., a marker, may be detectedfrom the image of the target instead of a region, and thus, a distancebetween the X-ray source and a marker, i.e., a distance between theX-ray source and the target may be acquired. This will be describedbelow.

FIG. 33 is a diagram of an X-ray apparatus 3000, according to anexemplary embodiment.

Referring to FIG. 33, the X-ray apparatus 3000 may include an imageacquirer 3100 and an X-ray radiator 3200. The X-ray radiator 3200 mayinclude a collimator 3230 and an X-ray source 3220, and the collimator3230 may include a lamp 3240 and a mirror 3400. The X-ray apparatus 3000may further include a controller, and include components that may beincluded in the above-described X-ray apparatuses.

For example, the lamp 3240 may be disposed on the side of the collimator3230, and the mirror 3400 may be disposed inside the collimator 3230.Light from the lamp 3240 may reflect from the mirror 3499 and betransmitted to a target. Furthermore, the controller of the X-rayapparatus 3000 may be replaced with a controller included in aworkstation.

When the lamp 3240 of the collimator 3230 is turned on, a center ofcrossing lines of the collimator 3230 may be projected on the target andshown as a dot on the target. According to an exemplary embodiment, thecenter of the crossing line of the collimator 3230 shown on the targetmay be used as a marker. By turning the lamp 3240 on and off, the markermay be shown and not shown on the target. The target may be an object oran X-ray detector. The image acquirer 3100 may acquire an image byimaging a target on which a marker is shown.

A location of the marker in the image may vary according to a distancebetween an X-ray source 3220 and the target. Therefore, the X-rayapparatus 3000 may acquire the distance between the X-ray source 3220and the target based on the location of the marker in the image.

The X-ray apparatus 3000 may further include a memory. The memory maystore information related to locations of a marker in target imagescaptured according to distances between the X-ray source 3220 and thetarget. The information may be stored in a database based on valuesestimated in advance through experiments.

A controller may detect the marker in the image of the target, andacquire the distance between the X-ray source 3220 and the target basedon the location of the marker in the image and relationship informationstored in the memory.

Although FIG. 33 illustrates that an LOS of the image acquirer 3100 isparallel to an LOS of the collimator, exemplary embodiments are notlimited thereto. The LOS of the image acquirer 3100 may be inclined withrespect to the LOS of the collimator as in FIG. 30.

FIG. 34 is a diagram for describing a location of a marker in an imageof a target when the target is moving in a space.

Referring to FIG. 34, locations X, X₁, X₂, and X₃ of a marker, which areprojections of a center X_(L) of crossing lines of a collimatorprojected onto a target, change according to locations of the target ina space. The marker represents a center X_(L) of crossing lines of acollimator. When a location of the marker in the space is X, a locationof the marker in the image of the target is X_(R). The location of themarker in the image of the target changes according to the locations ofthe target in the space. The location of the marker in the image maymove along an epipolar line L₁. In FIG. 34, e_(R) and e_(L) representepipoles, and O_(R) and O_(L) represent centers of projections.

That is, when the target moves on an irradiation window of thecollimator in a vertical direction and thus a distance between an X-raysource and the target changes, the marker in the image of the targetmoves in a horizontal direction along the epipolar line L₁.

FIGS. 35A to 35C are examples of object images according to distancesSOD1, SOD2, and SOD3 between an X-ray source and an object.

Referring to FIG. 35, respective locations of markers M1, M2, and M3 inan object image changes according to the distances SOD1, SOD2, and SOD3between the X-ray source and the object. In FIG. 35, the markers M1, M2,and M3 indicate a center of crossing lines of a collimator shown on theobject. When a lamp of the collimator is turned on, the center of thecrossing lines of the collimator may be projected onto the object andthus be shown as the markers M1, M2, and M3.

According to the distances SOD1, SOD2, and SOD3, the markers M1, M2, andM3 in the object image may move in a horizontal direction along anepipolar line L1. The epipolar line L1 is a path via which a marker inan image may move.

Although FIGS. 35A to 35C are related to a distance (SOD) between theX-ray source and the object and an object image, the examples of FIGS.35A to 35C may also be applied to a case of acquiring a distance (SID)between the X-ray source and a detector. That is, a location of a markerin an image of the detector may vary according to the distance (SID)between the X-ray source and the detector.

The epipolar line L1 may be acquired in advance by using a plurality ofimages of a target that are captured by changing the distance betweenthe X-ray source and the target. The epipolar line L1 may be acquired byconnecting markers detected from the target images. The epipolar line L1may be acquired during a calibration process. The calibration processcan include adjusting an estimation value of an X-ray apparatus to becloser to a true value. The X-ray apparatus may acquire parametersnecessary for controlling of the X-ray apparatus during the calibrationprocess.

Although an example of using the center of the crossing lines of thecollimator shown on the target as the marker is described above, themarker may be shown on the target by using a different method, whichwill be described with reference to FIG. 36.

FIG. 36 is a diagram of an X-ray apparatus 4000, according to anexemplary embodiment.

Referring to FIG. 36, the X-ray apparatus 4000 may include an imageacquirer 4100 and an X-ray radiator 4200. The X-ray radiator 4200 mayinclude a collimator 4230 and an X-ray source 4220, and the collimator4230 may include a laser emitter 4300 and a mirror 4400. The collimator4230 may further include a lamp 4240. Although not illustrated in FIG.36, the X-ray apparatus 4000 may include the components that may beincluded in the above-described X-ray apparatuses.

Laser emitted from the laser emitter 4300 may be reflected by the mirror4400 and thus shown on a target as a marker. The marker may be a pointthat corresponds to a center of an irradiation region of the collimator4230.

The image acquirer 4100 may acquire an image of the target showing themarker by imaging. As described with reference to FIG. 35, a location ofthe marker in the image may change according to a distance between theX-ray source 4220 and the target. Therefore, the X-ray apparatus 4000may acquire a distance between an X-ray source 4220 and the target basedon the marker in the image.

The laser emitter 4300 may be turned on and off. By turning on and offthe laser emitter 4300, the marker may be shown and not shown on thetarget.

As described with reference to FIGS. 33 and 36, the marker, which can bea reference point for estimating the distance between the X-ray sourceand the target, represents the center of the crossing lines of thecollimator projected on the target. Alternatively, the marker may be apoint that is shown on the target by using a laser emitter. The X-rayapparatus may show or not show the marker on the target.

FIGS. 37A to 37E are diagrams for describing an example of detecting amarker in an image of a target, according to an exemplary embodiment.

FIG. 37A is an image of the target. FIG. 37A is an image captured byimaging the target when a marker is shown on the target by turning on alamp of a collimator.

FIG. 37B is a difference image acquired from the image of FIG. 37A. Animage acquirer may further acquire a second image that is captured byimaging the target while the lamp is turned off. The difference image isobtained by subtracting the second image from the image of FIG. 37A.Although FIGS. 37A and 37B show an example in which a center of crossinglines of the collimator shown on the target is used as a marker, a pointshown by using a laser emitter in the collimator may also be used as themarker. In this case, a second image for acquiring the difference imagemay be an image acquired by imaging the target while the laser pointeris turned off.

FIG. 37C is an image acquired by extracting a collimation region fromthe difference image of FIG. 37B. An example of the detecting of thecollimation region from the difference image is described above withreference to FIG. 21.

FIG. 37D is an image acquired by enlarging the collimation region ofFIG. 37C and performing template matching by using template images T1and T2. Template matching is performed to detect the crossing lines ofthe collimator from the image. A center of the crossing lines detectedby template matching may be detected as a marker. The crossing linesdetected by template matching may be emphasized in the image.

FIG. 37E is an image acquired by overlapping an epipolar line L1 on theimage of FIG. 37D. The epipolar line L1 may be acquired in advance, andan intersection of the detected crossing lines of FIG. 37D and theepipolar line L1 may be detected as a marker. The marker may be moreaccurately detected from the image by using the epipolar line L1.

The steps for detecting the marker from an image obtained by an imageacquirer shown in FIGS. 37A to 37E may be performed in a controller ofan X-ray apparatus or a controller of a workstation.

FIGS. 37A and 37E provide an example of detecting a marker from an imageof the target, however a method of detecting the marker is not limitedto the example shown in FIGS. 37A to 37E. All of the steps shown inFIGS. 37A to 37E may not be performed, but part of the steps may beperformed. For example, steps shown in FIGS. 37B and 37C may be omitted,and template matching shown in FIG. 37D may be performed with the imageof FIG. 37A. Alternatively, the marker may be detected from the image ofFIG. 37A by different image processing.

FIG. 38 is a diagram for describing a location of a marker in an imageof a target, according to an exemplary embodiment.

Referring to FIG. 38, a lens is used for photography of the target. Thelens may be included in an image acquirer. A marker may represent acenter of crossing lines of a collimator shown on the target, or a pointshown on the target by using a laser pointer.

A location ‘X’ of a marker shown on the target in a space and a location‘x’ of a marker in the target image may be defined as in Equation 1below.

X=(Z*x)/f  [Equation 1]

In Equation 1, ‘Z’ represents a distance between the lens and thetarget, and T represents a focal distance of the lens. The focaldistance T is determined according to characteristics of the lens.

FIG. 39 is a diagram of an X-ray apparatus 5000, according to anexemplary embodiment.

Referring to FIG. 39, the X-ray apparatus 5000 may include an imageacquirer 5100 and an X-ray radiator 5200. The X-ray radiator 5200 mayinclude a collimator and an X-ray source. In some exemplary embodiments,the X-ray apparatus 5000 may include the components that may be includedin the above-described X-ray apparatuses.

Referring to FIG. 39, markers M1 and M2 shown on a target according todistances d1 and d2 between the X-ray source and the target may belocated on a line L2. Also, respective locations of markers x1 and x2 inan image of a target may change according to the distances d1 and d2.

The line L2, which indicates locations of markers according to locationsof the target in a space, may be defined in X-Z coordinates as inEquation 2 below.

Z=aX+b  [Equation 2]

In Equation 2, ‘a’ and ‘b’ may be acquired during a calibration process.For example, by using two images of the target captured by changing adistance of the X-ray source and the target, constant values ‘a’ and ‘b’of Equation 2 may be acquired.

A distance ‘d’ between the X-ray source and the target may be defined asin Equation 3.

d=Z*cos(c)  [Equation 3]

In Equation 3, ‘c’ represents an inclined degree of the collimator withrespect to the image acquirer 5100. For example, an angle ‘c’ is anangle formed between an LOS of the image acquirer 5100 and an LOS of thecollimator. The angle ‘c’ may be within a range from 0° to 90°. When theLOS of the image acquirer 5100 is parallel to the LOS of the collimator,the angle ‘c’ may be 0°. The angle ‘c’ may be acquired during thecalibration process, as ‘a’ and ‘b’ of Equation 2.

By using Equations 1 to 3, the distance ‘d’ between the X-ray source andthe target may be defined as in Equation 4.

d=(b*f*cos(c))/(f−a*x)  [Equation 4]

In Equation 4, T represents a focal distance that is determinedaccording to characteristics of a lens of the image acquirer 5100, and‘a,’ ‘b,’ and ‘c’ may be acquired during the calibration process. ‘x’may be acquired according to a location of a marker in an image of thetarget. That is, when the marker is detected from the image of thetarget, the distance ‘d’ between the X-ray source and the target may beacquired based on a location of the marker.

FIG. 40 is a block diagram of an X-ray apparatus 6000, according to anexemplary embodiment.

Referring to FIG. 40, the X-ray apparatus 6000 includes an X-ray source6220 and a collimator 6230, an image acquirer 6100 and a controller6200.

The image acquirer 6100 may acquire an object image. The image acquirer6100 may include various imaging devices, such as a camera or acamcorder.

The controller 6200 may correspond to the controller included in theabove-described X-ray apparatuses. Whether or not described, the X-rayapparatus 6000 may include the components and features of theabove-described X-ray apparatuses. Also, the X-ray apparatus 6000 may becontrolled by the workstation 110 of FIG. 1.

The controller 6200 may detect a marker that is projected by acollimator 6230 from the image acquired by the image acquirer 6100. Thecontroller 6200 may acquire a distance SOD between an X-ray source 6220and the object based on a location of a marker in the image.

The controller 6200 may acquire SOD based on location information of themarker according to locations of the object. Furthermore, the controller6200 may acquire SOD further based on a focal distance of a lens that isused for imaging of the object, and an angle formed by the collimator6230 and the lens. Examples of this are described above with referenceto Equations 1 to 4.

The marker may represent a center of crossing lines of the collimator6230 shown on the object when a lamp of the collimator 6230 is turnedon, or a point shown on the object by using a laser emitter of thecollimator 6230.

The image acquirer 6100 may further acquire a second image by imagingthe object while the lamp of the collimator 6230 is turned off or whilethe laser emitter is turned off.

The controller 6200 may detect the marker by using a difference image ofan object image showing the marker and the second image.

The controller 6200 may detect the marker in the image based oninformation about an epipolar line, which can be a path via which themarker in the image may move. Accordingly, the marker may be moreaccurately detected from the image.

According to an exemplary embodiment, the SOD may be acquired based on alocation of a marker that can be a point in the image. Therefore, theSOD may be acquired regardless of complexity of the object. This isbecause even when there is a height difference in a surface of theobject or a size of the object is smaller than an irradiation region, ashape of the irradiation region may be irregularly distorted, but themarker is almost not affected by a size or a shape of a target. That is,a distance acquired based on the marker may be relatively more accurate.

When the SOD is acquired based on the collimation region, it may bedifficult to acquire a range or a center of the collimation region whenthe collimation region is distorted. Since the size of the collimationregion may have an error due to operation accuracy of the collimator6230 and operation error of the X-ray radiator, errors may be generatedwhen estimating a distance based on the collimation region. Therefore,according to an exemplary embodiment, regardless of the size of thecollimation region and even when the surface of the target is severelycurved or the target is a small area such as a hand or a foot, the SODmay be acquired accurately.

The controller 6200 may acquire a thickness of the object based on theacquired SOD. The controller 6200 may determine a difference between theSOD and an SID as the thickness of the object.

The SID may be acquired by using the same method as the SOD. Forexample, the image acquirer 6100 may acquire a third image by imaging anX-ray detector. The controller 6200 may detect a marker in the thirdimage, and acquire a distance (SID) between the X-ray source 6220 andthe X-ray detector based on the location of the marker. However, amethod of acquiring the SID is not limited thereto. As described above,the controller 6200 may use various ways to acquire the SID.

The controller 6200 may acquire an irradiation condition of the X-raysource 6220 based on the thickness of the object.

FIG. 41 is another exemplary block diagram of the X-ray apparatus 6000of FIG. 40.

Referring to FIG. 41, the X-ray apparatus 6000 may include the imageacquirer 6100 and the controller 6200, and additionally, a memory 6300,an output interface 6400, and an input interface 6500.

The memory 6300 may store information about a location of a markeraccording to locations of an object, a focal distance of a lens used forimaging of the object, an angle formed by a collimator 6230 and thelens, and information about an epipolar line. The controller 6200 mayacquire an SOD based on the information stored in the memory 6300 andthe location of the marker in an image.

Also, the memory 6300 may store information about a relationship betweenthe location of the marker in the image and the SOD. Similar to FIG. 19,the information stored in the memory 6300 may be table type information.

Also, the memory 6300 may further store information about a relationshipbetween a thickness of the object and an irradiation condition of anX-ray source 6220. Similar to FIG. 20, the information stored in thememory 6300 may be table type information.

The output interface 6400 may output the irradiation condition of theX-ray source 6220 acquired by the controller 6200.

The input interface 6500 may receive a user input for setting theirradiation condition by approving or changing the irradiation conditionthat is output by the output interface 6400.

When the irradiation condition is set by the user input, the controller6200 may control the X-ray source 6220 such that the X-ray source 6220radiates X-rays according to the irradiation condition.

FIGS. 42A to 42B are exemplary diagrams of the output interface 6400 inthe X-ray apparatus 6000 of FIG. 41, according to exemplary embodiments.

Referring to FIGS. 42A and 42B, on a screen, the output interface 6400may output a first UI 6410 for setting the irradiation condition of theX-ray source and a second UI 6420 for setting a size of the object. Theirradiation condition of the X-ray source may include a tube voltage,tube current, and an X-ray radiation time. The irradiation condition ofthe X-ray source may be set by the user via the first UI 6410.

The second UI 6420 may include an automatic estimation icon IC1 andicons IC2 to IC6 that correspond to a plurality of body types. In FIGS.42A and 42B, the icons IC2 to IC6 include a baby icon IC2, a child iconIC3, a small body type icon IC4, a medium body type icon IC5, and alarge body type icon IC6. However, icons are not limited thereto. One ofthe icons may be selected to set the size of the object. The icon may beselected by a user input, selected according to a default setting, orselected according to a previously acquired thickness of the object. Theoutput interface 6400 may display a selected icon differently from othericons.

In FIG. 42A, the medium average body type icon IC5 is selected. TheX-ray apparatus 6000 may output, on the first UI 6410, an irradiationcondition corresponding to a medium body type according to the selectedmedium body type icon IC5. The user may set the irradiation condition byapproving or changing the irradiation condition output on the first UI6410.

When a user input for selecting the automatic estimation icon IC1 in thesecond UI 6420 is received, the X-ray apparatus 6000 may automaticallyset the size of the object by determining the thickness of the object.For example, the X-ray apparatus 6000 may acquire an image of theobject, detect a marker in the image, and determine a distance (SOD)between the X-ray source and the object based on a location of thedetected marker. The X-ray apparatus 6000 may determine a thickness ofthe object based on a difference between an SID and the SOD. The X-rayapparatus 6000 may determine a body type of the object as one of aplurality of body types based on the determined thickness of the object.The output interface 6400 may select an icon that corresponds to thedetermined body type, and display the selected icon differently fromother icons.

In FIG. 42B, it is assumed that the X-ray apparatus 6000 has determinedthe body type of the object as a large body type. The output interface6400 may display the large body type icon IC6 differently from othericons. When the automatic estimation icon IC1 is selected in FIG. 42A,the screen of the output interface 6400 may be converted from FIG. 42Ato FIG. 42B.

Accordingly, the irradiation condition may be changed from theirradiation condition corresponding to the medium body type to anirradiation condition corresponding to the large body type, and thechanged irradiation condition may be displayed on the first UI 6410. Auser input for setting the irradiation condition by approving orre-changing the changed irradiation condition may be received. When theirradiation condition is set, the X-ray apparatus 6000 may control theX-ray apparatus such that the object is captured by using X-raysaccording to the set irradiation condition.

Heretofore, it is explained that the controller 6200 of the X-rayapparatus 6000 according to an exemplary embodiment acquires a distanceSOD between an X-ray source 6220 and the object based on the imageacquired by the image acquirer 6100. However, the exemplary embodimentmay also be performed in a workstation. That is, the above-describedfeatures may also be applied to a workstation.

FIG. 43 is a block diagram of an X-ray apparatus 7000, according toanother exemplary embodiment.

Referring to FIG. 43, the X-ray apparatus 7000 includes an X-ray source7220, a collimator 7230, and an image acquirer 7100. The X-ray apparatus7000 may further include a workstation 8000. The workstation 8000 mayinclude a communicator 8100, and a controller 8200.

The communicator 8100 may receive an image by imaging an object from theimage acquirer 7100.

The communicator 8100 may transmit a control signal for controloperations of the X-ray source 7220, the collimator 7230, and the imageacquirer 7100 from the controller 8200 to the X-ray source 7220, thecollimator 7230, and the image acquirer 7100. The communicator 8100 maybe configured to communicate with external devices such as servers, etc.

The controller 8200 may detect a marker that is projected by thecollimator 7230 from the image acquired by imaging the object which isreceived by the communicator 8100. The controller 8200 may acquire adistance SOD between the X-ray source 7220 and the object based on alocation of a marker in the image.

Whether or not described, the controller 8200 of the workstation 8000may include the components and features of the above-described thecontrollers of the X-ray apparatuses. In some exemplary embodiments, thecontroller 8200 may correspond to the controller 113 or 813 included inthe workstation 110 or 860 of FIG. 1 or 22.

The workstation 8000 may further include a memory, an output interface,and an input interface. The memory, the output interface, and the inputinterface of the workstation 8000 may perform above-described functionsor operations of the memory 6300, the output interface 6400, and theinput interface 6500 of the X-ray apparatus 6000 of FIG. 41, andrepeated descriptions thereof will be omitted.

FIG. 44 is a flowchart of a method of controlling an X-ray system,according to an exemplary embodiment.

Referring to FIG. 44, the X-ray system acquires an image by imaging anobject (S610). The X-ray system detects, from the acquired image, amarker that is shown on the object by using a collimator (S630). TheX-ray system may acquire a distance SOD between an X-ray source and theobject based on a location of a marker in the image (S630).

The marker may represent a center of crossing lines of the collimatorshown on the object when a lamp of the collimator is turned on, or apoint shown on the object by using a laser emitter.

The X-ray system may further acquire a second image by imaging theobject while the lamp of the collimator is turned off or while the laseremitter is turned off.

The X-ray system may detect the marker by using a difference image ofthe image acquired in operation S610 and the second image.

The X-ray system may detect the marker based on information about anepipolar line, which is a path by which the marker in the image maymove.

The X-ray system may acquire the SOD based on information about alocation of the marker according to locations of the object, a focaldistance of a lens used for imaging of the object, and an angle formedby the collimator and the lens.

The X-ray system may store information about a relationship between thelocation of the marker in the image and the SOD. The X-ray system mayacquire the SOD based on the stored information.

The X-ray system may acquire a thickness of the object based on the SOD.Also, the X-ray system may acquire an irradiation condition of the X-raysource based on the acquired thickness of the object.

The X-ray system may output the acquired irradiation condition. TheX-ray system may receive a user input for setting the irradiationcondition by approving or changing the output irradiation condition. TheX-ray system may control the X-ray source such that the X-ray sourceradiates X-rays according to the irradiation condition that is set bythe user input.

The X-ray system may acquire the SID by using the same method as theSOD. For example, the X-ray system may acquire a third image by imagingan X-ray detector. The X-ray system may detect a marker projected by thecollimator from the third image. The X-ray system may acquire a distance(SID) between the X-ray source and the X-ray detector based on thelocation of the marker in the third image. The X-ray system may acquirea difference between the SOD and the SID as the thickness of the object.

An operation method of the X-ray system of FIG. 44 may be performed bythe X-ray apparatuses, and the workstations described above. The methodof controlling the X-ray system may be performed according to thedescriptions above.

The exemplary embodiments above may be created as computer-executableprograms and implemented in a general digital computer executing theprograms by using a computer-readable recording medium.

The computer-readable medium may include recording media, such asmagnetic storage media (e.g., ROM, floppy disks, or hard disks), opticalrecording media (e.g., CD-ROMs, or DVDs), etc. and storage media such ascarrier waves (for example, transmission through an Internet).

It should be understood that exemplary embodiments described hereinshould be considered in a descriptive sense only and not for purposes oflimitation. Descriptions of features or aspects within each exemplaryembodiment should typically be considered as available for other similarfeatures or aspects in other exemplary embodiments. While one or moreexemplary embodiments have been described with reference to the figures,it will be understood by those of ordinary skill in the art that variouschanges in form and details may be made therein without departing fromthe spirit and scope as defined by the following claims.

What is claimed is:
 1. An X-ray apparatus comprising: an X-ray sourceconfigured to radiate X-rays; a collimator configured to adjust anirradiation region of X-rays radiated from the X-ray source; an imageacquirer configured to acquire an image by imaging an object; and acontroller configured to detect, in the image, a marker projected on theobject by the collimator, and to determine a source to object distance(SOD) based on a location of the marker in the image, wherein the SODcomprises a distance between the X-ray source and the object.
 2. TheX-ray apparatus of claim 1, wherein the marker represents at least onefrom among a center of crossing lines of the collimator projected on theobject by the collimator when a lamp of the collimator illuminates theobject, or a point projected on the object by a laser emitter of thecollimator.
 3. The X-ray apparatus of claim 2, wherein the imageacquirer is further configured to acquire a non-illuminated image byimaging the object while the object is not illuminated by the lamp ofthe collimator or the laser pointer, and the controller is furtherconfigured to detect the marker using a difference image generated fromthe image and the non-illuminated image.
 4. The X-ray apparatus of claim3, wherein the controller is further configured to detect the markerbased on information about an epipolar line comprising a path alongwhich the marker in the image is able to move.
 5. The X-ray apparatus ofclaim 1, wherein the controller is further configured to determine theSOD based on information about a location of the marker according to atleast one from among locations of the object, a focal distance of a lensused for imaging the object, and an angle between the collimator and thelens.
 6. The X-ray apparatus of claim 1, further comprising a memoryconfigured to store information about a relationship between a locationof the marker in the image and the SOD, wherein the controller isfurther configured to determine the SOD based on the information storedin the memory.
 7. The X-ray apparatus of claim 1, wherein the controlleris further configured to determine a thickness of the object based onthe SOD, and to determine an irradiation condition of the X-ray sourcebased on the thickness of the object.
 8. The X-ray apparatus of claim 7,further comprising: an output interface configured to display theirradiation condition determined by the controller; and an inputinterface configured to receive a user input setting the irradiationcondition by approving or changing the irradiation condition displayedby the output interface.
 9. The X-ray apparatus of claim 8, wherein thecontroller is further configured to control the X-ray source to radiateX-rays according to the irradiation condition set by the user input. 10.The X-ray apparatus of claim 7, wherein the image acquirer is furtherconfigured to acquire a detector image by imaging an X-ray detector, andthe controller is further configured to detect a marker projected by thecollimator from the detector image, to determine a source to imagereceptor distance (SID) based on a location of the marker in thedetector image, and to determine a difference between the SOD and theSID as the thickness of the object, wherein the SID is a distancebetween the X-ray source and the X-ray detector.
 11. A method ofcontrolling an X-ray apparatus comprising an X-ray source and acollimator, the method comprising: acquiring an image by imaging anobject; detecting, in the image, a marker projected on the object by thecollimator of the X-ray apparatus; and determining a source to objectdistance (SOD) based on a location of the marker in the image, whereinthe SOD comprises a distance between the object and the X-ray source ofthe X-ray apparatus.
 12. The method of claim 11, wherein the markerrepresents at least one from among a center of crossing lines projectedon the object by the collimator when a lamp of the collimatorilluminates the object, or a point projected on the object by a laseremitter of the collimator.
 13. The method of claim 12, furthercomprising acquiring a non-illuminated image by imaging the object whilethe object is not illuminated by the lamp of the collimator or the laserpointer, and wherein the detecting of the marker comprises detecting themarker using a difference image generated from the image and thenon-illuminated image.
 14. The method of claim 13, wherein the detectingof the marker comprises detecting the marker based on information aboutan epipolar line comprising a path along which the marker in the imageis able to move.
 15. The method of claim 11, wherein the determining ofthe SOD comprises determining the SOD based on information about alocation of the marker according to at least one from among locations ofthe object, a focal distance of a lens used for imaging the object, andan angle between the collimator and the lens.
 16. The method of claim11, further comprising storing information about a relationship betweena location of the marker in the image and the SOD, wherein thedetermining of the SOD comprises determining the SOD based on theinformation stored in the memory.
 17. The method of claim 11, furthercomprising: determining a thickness of the object based on the SOD; anddetermining an irradiation condition of the X-ray source based on thethickness of the object.
 18. The method of claim 17, further comprising:displaying the determined irradiation condition; and receiving a userinput setting the irradiation condition by approving or changing theirradiation condition displayed on the output interface.
 19. The methodof claim 18, further comprising controlling the X-ray source to radiateX-rays according to the irradiation condition set by the user input. 20.A non-transitory computer-readable recording medium having recordedthereon a program, which, when executed by a computer, causes thecomputer to perform the method of claim 11.